An experimental study was designed to determine the effect, in dogs' tendons immobilized by a scar-evoking procedure, of a two-month delay in tendon grafting after excision of the scar. The procedure was compared with one where grafting had been done at the time of excision of the scar. The results were evaluated by assessing the excursion of the repaired tendons and by histological examination. In the Delayed Graft Group, 50 per cent of the grafts were considered successful. In the Primary Graft Group, 14 per cent of the grafts were considered so. This study emphasizes only one aspect of the tendon graft problem, that is, the influence of the nature of the bed into which a free tendon graft is placed.