This study aims to investigate the effects of a proximally-based turnover sheath flap obtained from the tendon sheath on the prevention of adhesion formation in the legs of the chickens whose tendons and sheaths have been injured. The chickens were categorised into 4 groups. Group 1 was chosen as the sham group. In Group 2, a defective area of 0.3 x 0.5 cm was created across the sheath, without damaging the tendon. The healthy profundus tendons of the chickens in Group 3 were cut and repaired. Afterwards, a defective area of 0.3 x 0.5 cm was created across the tendon sheath. In Group 4, the healthy profundus tendons were cut and repaired. Then, a defective area of 0.3 x 0.5 cm was created over the reconstructed tendon. This defective area was finally covered with a proximally-based turnover sheath flap of the size 0.4 x 1 cm, which was raised from the distal part of the sheath. The toes were immobilised for 3 weeks before the chickens were sacrificed. Histopathological and biomechanical analyses showed adhesion in the repaired tendons in Group 3, in which movement restriction was shown by biomechanical analyses. The present study showed that covering the defective sheath that was created over the repaired tendon with a proximally-based turnover tendon sheath flap prevented peritendinous adhesion. (c) 2008 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.