Although there are sporadic reports of pregnancies using semen after long-term cryopreservation, there are no data on the success rate of this procedure and its clinical feasibility. Between 1969 and 1980, 475 men deposited semen specimens prior to vasectomy or therapeutic sterilization. Prefreeze sperm counts and motility were significantly higher in the prevasectomy group. Later, 5 wives of 177 vasectomized men and 16 wives of 183 therapeutically sterilized men returned for artificial insemination with their husbands' semen. Only 1 conception resulted among the 21 women. This occurred after a single insemination of a 7-year-old specimen obtained prevasectomy. The post-thaw motility of this specimen (45%) was better than that of most other thawed specimens. Post-thaw motilities were unpredictable despite comparable prefreeze motilities. Because of this unpredictability, semen cryopreservation is clearly no guarantee of "fertility insurance".