A knowledge of the response of prolactin secretion to drug stimulation is required for the better understanding of infertility associated with hyperprolactinemic states. The dynamics of prolactin secretion was investigated in 30 ovulatory females subjected to sulpiride stimulation. Prolonged dynamic tests are inappropriate procedures for screening purposes and basal value determinations present a weak correlation with the curve area (rs = 0.485; P less than 0.005). On the contrary, a high statistical correlation (rs = 0.861; P less than 0.001) was found between the curve area and the hormonal value 30 min after sulpiride administration. We conclude that basal prolactin levels and the 30-min value after sulpiride administration seem to be sufficient and valid representative estimations in the screening of abnormal prolactin secretion states.