Postvasovasostomy intravasal pressure recordings in ten mongrel dogs were used to evaluate the effect of location of vasectomy and severance of the neurovascular sheath of the vas deferens on peristalsis of the proximal portion of the vas deferens. Preservation of the neurovascular sheath at the time of vasectomy and the proximal location of the vasectomy may play a role in preservation of vasal peristalsis and normal sperm transport after vasovasostomy. The testicular histologic features were normal before and after vasovasostomy in all animals studied.