A method for anchoring a foundation structure (3) in a seabed (1) that includes introducing a receiving structure (6) into the seabed, lowering a support post (5) of the foundation structure (3) into the receiving structure (6), producing a connection between the receiving structure (6) and foundation structure (3) by filling the receiving structure (6) with a curable filling compound (7), and curing the curable filling compound (7), wherein the support post (5) is fixed in the receiving structure (6) prior to filling the receiving structure (6) with the curable filling compound (7). Also disclosed is a foundation structure (3) for an offshore wind turbine, for anchoring in a seabed (1), which includes at least one support post (5) to be introduced into a receiving structure (6), which has fixing elements (11, 20) for temporarily fixing in the receiving structure (6) before grouting is carried out.