UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of October 2026

Commission File Number: 001-36515

Materialise NV

Technologielaan 15

3001 Leuven

Belgium

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F x Form 40-F ¨

This Form 6-K is incorporated by reference into the registrant’s Registration Statement on Form F-3 (File No. 333-213649).

Third Quarter 2026 Results

Except as otherwise required by the context, references to “Materialise,” “Company,” “we,” “us,” and “our” are to Materialise NV and its subsidiaries.

Third Quarter 2026 Financial Results

Total revenue for the third quarter of 2026 increased by 2.1% to 67,670 kEUR from 66,259 kEUR for the third quarter of 2025.

Revenue from our Materialise Medical segment increased 9.7% to 36,542 kEUR for the third quarter of 2026 compared to 33,296 kEUR for the same period in 2025.

Revenue from our Materialise Software segment was 9,864 kEUR for the third quarter of 2026 compared to 10,286 kEUR for the same quarter last year.

Revenue from our Materialise Manufacturing segment was 21,266 kEUR for the third quarter of 2026 compared to 22,677 kEUR for the third quarter of 2025.

Gross profit increased 3.7% to 39,035 kEUR for the third quarter of 2026 compared to 37,651 kEUR for the same period last year. Gross profit as a percentage of revenue was 57.7% compared to 56.8% for the third quarter of 2025.

Research and development (“R&D”), sales and marketing (“S&M”), and general and administrative (“G&A”) expenses increased, in the aggregate, by 7.8% to 38,830 kEUR for the third quarter of 2026 from 36,019 kEUR for the third quarter of 2025 mainly driven by 11.9% higher R&D spend.

Net other operating income was 1,137 kEUR compared to 890 kEUR for the third quarter of 2025.

Net operating income in the third quarter of 2026 includes non-recurring charges of 184 kEUR from the impairment of inventory related to the transfer of the Eyewear assets.

Operating profit was 1,343 kEUR for the third quarter of 2026, compared to 2,522 kEUR for the third quarter of 2025.

Net financial result was 160 kEUR for the third quarter of 2026, compared to (121) kEUR for the third quarter of 2025.

The third quarter of 2026 contained net tax expenses of (120) kEUR, compared to net tax expenses of (553) kEUR in the third quarter of 2025.

As a result of the above, net profit for the third quarter of 2026 was 1,383 kEUR, compared to 1,848 kEUR for the same period in 2025.

Cash flow from operating activities for the third quarter of 2026 amounted to 9,666 kEUR compared to 10,359 kEUR for the same period in 2025. Total cash used for capital expenditures for the third quarter of 2026 amounted to 2,146 kEUR and free cash flow after operating and investing activities was 11,419 kEUR.At September 30, 2026, cash and cash equivalents increased to 153,529 kEUR from 133,918 kEUR at December 31, 2025.

Gross debt increased to 71,056 kEUR from 63,113 kEUR at December 31, 2025. As a result, our net cash position increased by 11,668 kEUR to 82,473 kEUR compared to 70,805 kEUR as of December 31, 2025. At the end of the third quarter of 2026 Materialise had repurchased 1,426,784 own shares for a total amount (excluding transaction cost) of 7,482 kEUR (8,698 kUSD) under its previously announced share buy-back program.

Net shareholders' equity at September 30, 2026 increased to 255,809 kEUR compared to 255,482 kEUR at December 31, 2025.

Adjusted EBIT amounted to 2,485 kEUR for the third quarter of 2026 compared to 2,918 kEUR for the 2025 period. The Adjusted EBIT margin (Adjusted EBIT divided by total revenue) for the third quarter of 2026 was 3.7%, compared to 4.4% for the third quarter of 2025. Adjusted EBITDA for the third quarter of 2026 amounted to 8,046 kEUR compared to 8,428 kEUR for the 2025 period.

Adjusted EBITDA from our Materialise Medical segment amounted to 10,015 kEUR for the third quarter of 2026 compared to 10,199 kEUR for the corresponding period in 2025, while the Adjusted EBITDA margin for the segment (segment Adjusted EBITDA divided by segment revenue) was 27.4% compared to 30.6% for the third quarter of 2025.

Adjusted EBITDA from our Materialise Software segment amounted to 1,463 kEUR for the third quarter of 2026 compared to 1,801 kEUR for the corresponding period in 2025, while the Adjusted EBITDA margin for the segment was 14.8% compared to 17.5% for the prior-year period.

Adjusted EBITDA from our Materialise Manufacturing segment improved to (257) kEUR for the third quarter of 2026 compared to (845) kEUR for the same period in 2025, while the Adjusted EBITDA margin for the segment was (1.2)% compared to (3.7)% for the third quarter of 2025.

Non-IFRS Measures

Materialise uses EBIT, EBITDA, Adjusted EBIT and Adjusted EBITDA as supplemental financial measures of its financial performance, including for purposes of monitoring compliance with financial covenants, supporting discussions with financing institutions, and meeting reporting requirements to our banks. EBIT is calculated as net profit plus income taxes, financial expenses (less financial income) and shares of profit or loss in a joint venture. EBITDA is calculated as net profit plus income taxes, financial expenses (less financial income), shares of profit or loss in a joint venture and depreciation and amortization. Adjusted EBIT and Adjusted EBITDA are determined by adding to EBIT and EBITDA, respectively (i) share-based compensation expenses, (ii) acquisition expenses related to business combinations or divestiture-related expenses, (iii) impairments and revaluation of fair value due to business combinations and (iv) costs incurred in relation to corporate initiatives, restructurings or reorganizations that are of a non-recurring nature. Management believes these non-IFRS measures to be important measures as they exclude the effects of items which primarily reflect the impact of financing decisions and, in the case of EBITDA and Adjusted EBITDA, long term investment, rather than the performance of the company’s day-to-day operations. The company also uses segment Adjusted EBITDA and segment Adjusted EBITDA margin to evaluate the performance of its three business segments. As compared to net profit, these measures are limited in that they do not reflect the cash requirements necessary to service interest or principal payments on the company’s indebtedness and, in the case of EBITDA and Adjusted EBITDA, these measures are further limited in that they do not reflect the periodic costs of certain capitalized tangible and intangible assets used in generating revenues in the company’s business, or the changes associated with impairments. Management evaluates such items through other financial measures such as financial expenses, capital expenditures and cash flow provided by operating activities. The company believes that these measurements are useful to measure a company’s ability to grow or as a valuation measurement. The company’s calculation of EBIT, EBITDA, Adjusted EBIT and Adjusted EBITDA may not be comparable to similarly titled measures reported by other companies. EBIT, EBITDA, Adjusted EBIT and Adjusted EBITDA should not be considered as alternatives to net profit or any other performance measure derived in accordance with IFRS. The company’s presentation of EBIT, EBITDA, Adjusted EBIT and Adjusted EBITDA should not be construed to imply that its future results will be unaffected by unusual or non-recurring items.

Exchange Rate

This document contains translations of certain euro amounts into U.S. dollars at specified rates solely for the convenience of readers. Unless otherwise noted, all translations from euros to U.S. dollars in this document were made at a rate of EUR 1.00 to USD 1.1355, the reference rate of the European Central Bank on September 30, 2026.

About Materialise

Materialise NV incorporates more than three decades of 3D printing experience into a range of software solutions and 3D printing services that empower sustainable 3D printing applications. Our open, secure, and innovative end-to-end solutions enable flexible industrial manufacturing and mass personalization in various industries — including healthcare, automotive, aerospace, art and design, wearables, and consumer goods. Headquartered in Belgium and with branches worldwide, Materialise NV combines the largest group of software developers in the industry with one of the world's largest and most complete 3D printing facilities. For additional information, please visit: www.materialise.com.

Consolidated income statements (Unaudited)

Consolidated statements of comprehensive income (Unaudited)

Consolidated statement of financial position (Unaudited)

Consolidated statement of cash flows (Unaudited)

Reconciliation of Net Profit (Loss) to EBITDA and Adjusted EBITDA (Unaudited)

(1) Share-based compensation expense represents the cost of equity-settled and share-based payments to employees.

(2) Non-recurring costs related to corporate initiatives, restructurings or reorganizations.

(3) Impairments represent the impairment of tangible and intangible assets and inventory of RapidFit NV and Eyewear resulting from the transfer of the assets to their respective management teams.

(4) Divestitures-related expenses represent fees and costs in connection with the divestitures of RapidFit and Eyewear.

Reconciliation of Net Profit (Loss) to EBIT and Adjusted EBIT (Unaudited)

(1) Share-based compensation expense represents the cost of equity-settled and share-based payments to employees.

(2) Non-recurring costs related to corporate initiatives, restructurings or reorganizations.

(3) Impairments represent the impairment of tangible and intangible assets and inventory of RapidFit NV and Eyewear resulting from the transfer of the assets to their respective management teams.

(4) Divestitures-related expenses represent fees and costs in connection with the divestitures of RapidFit and Eyewear.

Segment P&L (Unaudited)

(1)  Unallocated segment adjusted EBITDA consists of corporate research and development and corporate other operating income (expense), and the added share-based compensation expenses, acquisition expenses related to business combinations or divestiture-related expenses, impairments and revaluation of fair value of business combinations and non-recurring costs related to corporate initiatives, restructurings and reorganizations that are included in Adjusted EBITDA and that are not allocated to the reporting segments .

Reconciliation of Net Profit (Loss) to Segment adjusted EBITDA (Unaudited)

(1) Impairments represent the impairment of tangible and intangible assets and inventory of RapidFit NV and Eyewear resulting from the transfer of the assets to their respective management teams.

(2) Costs related to restructuring activities and organizational changes within specific reported business segments, including personnel-related and other associated expenses.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: October 29, 2026