A surgical implant (1) adapted for repairing a tissue or muscle wall defect comprises an areal, flexible basic structure which defines a primary region (4) and at least one arm (6) starting from the primary region (4) and having a free end and an end area extending up to the free end. The arm (6) is folded back and fixed (e.g. welded, sutured or glued), in its end area, to the primary region (4) of the basic structure. Preferably, the basic structure (4, 6) is made from one piece and comprises a mesh.