Increased hypothalamic dopamine turnover may prevent the ovulatory LH peak by different mechanisms and may in this way result in anovulation. Ten patients with anovulatory menstrual cycles who had been treated with clomiphene citrate without success were given the dopaminolytic drug pimozide (Antalon) at a dose of 5 mg/day orally either from day 7 to day 11 (7 women; group 1) or from day 11 to day 15 of the menstrual cycle (4 women; group 2). One patient from group 2 ovulated during the treatment cycle. A further woman from this group exhibited an LH peak, but did not ovulate, whereas a slow increase of the circulating LH level was recorded in the remaining two patients. Systematic investigations should clarify whether introduction of dopaminolytic therapy in the treatment of hypothalamic anovulation may be justified.