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 May 2025 Commission File No. 001-35193 Grifols, S.A. Form 20-F x Form 40-F ¨ G r i fo l s, S.A. TABLE OF CONTE N T S S e q u e n t i a l P a g e N u m b e r 1. E a rn i n g s P r e s s R e l e a s e , d a t e d M a y 1 2, 2 0 2 5 2. Q 1 2 0 2 5 E a rn i n g s P r e s e n t a t i o n 3 5 (Translation of r ...