This procedure was devised in an attempt to treat azoospermia caused by severe vas obstruction. An artificial spermatocele is prepared by resection of the vas slightly distal to the epididymal-deferential ansa and anastomosing onto its proximal stump a piece of Dardik's prosthesis sealed at the far end. During the partner's ovulatory period the spermatocele fluid is aspirated, mixed with fertile donor seminal plasma and used for artificial insemination. To date 8 subjects have had the operation: spermatocele fluids of 4 contained some highly motile spermatozoa with normal ability to penetrate cervical mucus for some months. Spermatocele implantation onto the vas apparently has the following advantages: the anatomic and functional integrity of the epididymis is maintained, the storage function of the epididymal-deferential ansa is preserved, and the risk of spermatocele collapse seems to be reduced by the high "vis a tergo" developed during ejaculation.