Artificial insemination--homologous (AIH) treatment in 100 couples is presented. An uncorrected pregnancy rate of 13% was achieved therapeutically versus a 10% spontaneous pregnancy rate. An adjusted pregnancy rate for those who conceived or completed at least six cycles of treatment was 41%. A pregnancy rate of 8% was obtained in 25 cases of oligospermia (less than 20 X 10(6)/ml), 15% in 27 cases of decreased motility only (less than 45% active), 27% in 18 cases of unexplained poor postcoital tests and 28% in 18 couples with suspected or proven immunologic problems. The most important reason for lack of success in our series appeared to be failure to continue therapy for an adequate period, defined as a minimum of six cycles. Since indications for AIH are less well defined than for artificial insemination with donor (AID), pregnancy yields are less reliable as an indication of a causal relationship.