: Polycystic ovary syndrome (PCOS) as well as hyperprolactinemia can cause infertility. In retrospective study the prolactin levels during the oral metoclopramide test among lean PCOS woman according to four phenotypes and free androgen index (FAI) were compared. The study population consisted of 314 lean PCOS women. The population was divided into four groups according to the FAI and menstrual cycle regularity. The group A consisted 126 women with FAI≥5 and irregular menstruation, the group B- 53 patients with FAI≥5 and regular menstruation. Group C- 70 patients with FAI<5 and irregular menstruation, group D - 65 patients with FAI<5 and regular menstruation. The ratio of prolactin value in 120th minute in the metoclopramide test to the basal prolactin value was higher in group D than in groups A and B. The prolactin basal concentration was higher in patients with FAI≥5 than in patients with FAI<5, (262.9 vs 228.9 µIU/ml; p<0.001). The ratio of prolactin in 60th minute (12.3 vs 16.7; p=0.006) and in the 120th minute (10.9 versus 13.3; p<0.001) of the metoclopramide test to the basal prolactin were lower in patients with FAI≥5. The prolactin secretion in lean PCOS women may be associated with their FAI.