This open, prospective, noncomparative study evaluated clinical and metabolic aspects of the use of a contraceptive combination of ethinyl estradiol (30 microg) and gestodene (75 microg) continuously for 24 weeks in 45 women aged 25 +/- 3.7 years. No alterations in weight or blood pressure were observed. Few side effects were recorded. Amenorrhea rates increased from the fourth month of observation onwards, reaching 81.2% by week 24. A reduction in the levels of cholesterol and LDL and an increase in HDL and triglycerides were observed. Insulin levels increased but not significantly, while levels of glycemia remained unchanged. Levels of antithrombin III, fibrinogen and plasminogen activator inhibitor-1 (PAI-1) increased, whereas a reduction was observed in proteins C and S and in prothrombin time (PT). Activated partial thromboplastin time (APTT) remained unchanged. The treatment was associated with satisfactory clinical effects, high rates of amenorrhea after the third treatment cycle, and resulted in metabolic changes similar to those encountered during the classic use of contraceptive pills with monthly interruption for withdrawal bleeding.