A suture sleeve for securing a medical implantable lead in position in relation to a human or animal body, has a tubular body of a resilient material defining a through bore in the longitudinal direction of the suture sleeve and being formed with one or more longitudinal spaced, circumferential suture grooves on the outside and two or more grip enhancing projections around the inner circumference of the through bore in at least an area radially inward of a suture groove. The suture sleeve is formed with two or more stiffening protuberances in the bottom along the circumference of the suture groove such that the bottom of the suture groove deviates from circular as seen in cross section. The, stiffening protuberances are positioned radially outside of the respective grip enhancing projections on the inside. A method for manufacturing such a suture sleeve is also described.