The profundus tendons of young adult chickens have been used to study flexor tendon healing within the digital sheath. Histological observation has shown that the preserved digital sheath prevented the tendon healing with adhesions and that the epitendon played a leading role in the process of tendon repair. Muscle tension must be removed from the sutured site for tendon repair without adhesion. Post-operative immobilisation in the “tension-reducing position”, in which an operated digit is flexed and the rest of the digits are extended, is believed to be one of the most efficient procedures for removing tension from the sutured site of the tendon. Three methods of tendon suture were used — Bunnell crisscross stitch, modified double right-angle suture, and interrupted suture. Least adhesions were noted in the tendons sutured by interrupted suture, and the tensile strength of the tendons sutured by interrupted suture tended to be highest between three and six weeks postoperatively. To achieve tendon healing with good gliding function, the following procedures should be observed: (1) preservation of the digital sheath, (2) an atraumatic technique for tendon suture, and (3) immobilisation in the “tension-reducing position”.