We report on 332 infertile couples who underwent 1115 cycles of intrauterine insemination (IUI) with washed husband's semen. The indication for IUI was an abnormal post-coital test due to either a male or cervical infertility factor. The mean number of IUI cycles per patients was 3.4, the overall pregnancy rate 18.7%, and the pregnancy rate per cycle 5.6%. The cumulative pregnancy rate calculated by life table analysis showed that 16.0% of pregnancies occurred in the first three treatment cycles, while the cumulative pregnancy rate was 26.9% by the sixth cycle. The outcome of the therapy was adversely affected if the woman's age was > 39 years and/or total motile sperm count per insemination was < 1 x 10(6). No pregnancy occurred in women older than 44 years or in cases with a total motile sperm count before semen preparation of < 1 x 10(6).