From July 1975 to December 1979 at the Univ.-Klinik für Frauenheilkunde, Innsbruck, 91 female sterile patients were examined due to hyperprolactinaemia. Since hyperprolactin presents common symptoms of different diseases, we established a differentiated clarification and therapy scheme using the guidelines of the W.H.O. and all new knowledge. After disqualification of patients with corresponding tubular sterility, we induced in 24 patients 32 pregnancies with medication or operative therapy. After birth or abortion a prolactin-caused dysfunction reappeared in the reproductive system. With a gradual prolactin increasion in the serum level, the grade of this dysfunction in the reproductive system was worsened. A reduction of the prolactin serum level to 40 ng/ml seems to be the basis for spontaneous ovulation. Present therapeutic possibilities and as a result the reversibility of this disturbance after interruption of prolactin inhibitors, we find that long-therm therapy is necessary.