Parenteral, depot, repeatable bromocriptine Parlodel LARR (PLO LAR) was used in the treatment of 10 women with hyperprolactinaemia. Two of them had previously an operation of a prolactinoma, eight did not have adenomas. Twenty eight days following administration of 50 mg PLO LAR, the PRL levels ere significantly lower than before treatment; in patients without adenomas they were quite normal. The action of the mentioned 50 mg PLO LAR corresponded roughly to a daily dose of 7.5 mg ParlodelR (PLO) by the oral route, i.e. in 28 days a total of 185 mg bromocriptine. After administration of five PLO LAR injections (50 and later 100 mg), the mean PRL levels in patients without adenomas were normal after 6 months. There were no significant nor pathological changes 28 days following i.m. PLO LAR 50 mg as regards T3, T4 levels, the blood sugar, cholesterol, FSH, LH, STH, TSH, testosterone cortisol, progesterone, 17 beta-estradiol, androstendione, 11 beta-OH androstendione, DHEA-S, 17 alpha-OH progesterone, aldosterone, 17-ketosteroids and 17-ketogenic steroids (in urine). LHRH + TRH + insulin tolerance tests were made repeatedly. Significant changes were found only in PRL levels (decline). In three amenorrhoic patients the originally low progesterone level rose significantly to levels of postovulation progesterone. One of these three women became pregnant after 18 years of unsuccessful treatment of sterility, incl. various oral dopaminergic preparations. The patients tolerated the preparation well and various biochemical and haematological tests were normal. The effect on galactorrhoea was favourable, seven amenorrhoic women had normal menstruation.