The purpose of this study was to evaluate the success of gamete intrafallopian transfer (GIFT) and superovulation with intra-uterine artificial insemination (S-IUI) in couples with long-term unexplained infertility. Thirty-nine couples were offered three attempts at each treatment. Sixty-three IUI cycles were completed with a pregnancy rate of 1.5% per cycle. Forty-nine GIFT procedures were carried out with a pregnancy rate of 26.5% per cycle. The cumulative conception rate after three cycles of GIFT was 0.56. GIFT appears to offer a far greater chance of pregnancy than S-IUI in unexplained infertility.