We studied the effect of flexor tendon sheath closure on flexor tendon function after delayed primary flexor tendon suture in white leghorn chickens. The tendon suture was carried out after a tendon laceration. In the left foot the tendon sheath was closed after tendon suture, and in the right the sheath was excised over the tendon suture. Tendon gliding, joint motion, the fate of the closed sheath, peritendinous adhesions, and tendon healing were studied. The sutured sheath disappeared after suturing and was associated with poor tendon healing. Sheath closure did not improve flexor tendon function in a delayed primary repair.