The results of therapy of 226 women receiving frozen and fresh donor semen are reported. Overall, 45.6% of patients conceived with a monthly fecundability of 0.102. The effect of a variety of factors on fertility rates was analyzed in life-table analysis of 1000 cycles. Optimal pregnancy rates were obtained in couples with azoospermia (0.17) or no female infertility factors (0.2). Patients with ovulatory dysfunction treated with clomiphene also had optimal pregnancy rates (0.17 per cycle). Endometriosis reduced fecundability significantly (0.04 per cycle). There was no significant difference in pregnancy rates per cycle between fresh (0.12) and frozen (0.09) semen. Acceptable pregnancy rates were obtained with frozen semen therapy and in patients with treated ovulatory dysfunction.