Thirty-seven women with cyclical mood changes, either only in the premenstrual phase ('pure PMS') or during the entire cycle with premenstrual aggravation ('PMA'), were recruited to participate in a randomized study investigating the effect of three different oral contraceptives (OCs) on mood symptoms; 32 out of the 37 women completed the study. The monophasic ethinylestradiol (EE)/desogestrel (DSG) OC was compared, in a single (doctor)-blind cross-over design, with a monophasic and a triphasic levonorgestrel (LNG)-containing combined OC. The women kept a record of their symptoms and complaints by noting daily ratings using a validated visual analogue scale. One pretreatment cycle was followed by four treatment cycles, two cycles on each OC. All OCs had a beneficial effect on the PMS symptoms compared to the pre-treatment period. There were no changes between consecutive cycles. Cyclical symptom changes were noted during all OC treatment. The monophasic desogestrel pill provoked less changes in mood parameters than the monophasic and triphasic levonorgestrel OCs. However, physical complaints were less frequently reported during the use of the triphasic preparation as compared to the monophasic desogestrel preparation. Women with 'pure' PMS (premenstrual syndrome) were more consistent in their reactions on OCs compared to women with PMA.