Immediate mobilization of flexor tendons repairs creates a conflict between muscle strength and suture solidity. Non removable sutures are brittle and require to prevent extension by means of either a cast in flexion of the wrist and of the metacarpo-phalangeal joints or a rubber band traction. Pull-out sutures do not permit early mobilization because of their anchorages. The authors present a new technique they have been using for the last five years. It consists in a simple solid slip-knot which tightening the tendon when the muscle pulls. This knot is fixed at the distal bone insertion of the tendon, which makes immediate mobilization possible. Sixty three patients have been treated with by this technique over the past five years. We have not encountered any rupture of the suture. The results, even in the least favorable cases have been considered as very good.