A prospective study of 113 personal consecutive microsurgical reversals of female sterilization during the 6-year period from 1979 to 1984 was carried out to determine factors affecting the pregnancy rate. The sterilizations were performed by laparoscopic unipolar coagulation in 54% of the patients, by the Pomeroy technique in 28%, by fimbriectomy in 8%, by the Irving operation in 5%, and by clips or rings in 4%. In the group with no minimum follow-up period, 50% had intrauterine pregnancies and 5% had ectopic gestations. Eighty-nine patients had at least 12 months of follow-up after reversal surgery. This group is studied in detail. Factors affecting the pregnancy rate were length of tube, type of sterilization performed, anastomotic site, and availability of both tubes for reconstruction. Age, parity, and interval from sterilization to reversal surgery did not affect the pregnancy rate. Fifty percent of the intrauterine pregnancies were conceived within 6 months of reversal surgery.