An oral contraceptive containing gestodene (Minulet) was examined in collaborating with the Richter-Wyeth Pharmaceutical Factory. The authors present their experiences of monitoring of 591 cycles of a hundred women between 18 and 35 years of age. There were no pregnancy and severe side effects during that period. Irregular bleeding occurred in 17.5% of women in the beginning of the treatment, however it gradually decreased and ceased by the fifth cycle. Both the length and the quantity of the withdrawal bleeding decreased by the end of the sixth cycle. During the observation there was no amenorrhoea and the dysmenorrhoea presented a decreasing tendency, expressing in per cent of the cycles. Their own data support, that the oral contraceptives containing gestodene meet requirements of today's medical science, and beyond the low hormone content they also fulfil the next demands: reliable contraceptive effect, efficacy, excellent cycle control, good tolerability and limited side effects.