Fifty-six cycles of gamete intrafallopian transfer (GIFT) were performed after programming by administration of norethisterone in the previous cycle. Ovarian hyperstimulation was achieved with clomifene citrate and human menopausal gonadotropins. Only one GIFT was performed during a weekend (1.8%). The implantation rate was 41.1% and the evolutive pregnancy rate 30.4%. The endocrinological influence of these regimens are discussed by comparison of those observed in an in vitro fertilization program. The main influence is a decreased serum luteinizing hormone (LH) level in the preovulatory phase.