Levonorgestrel, 0.15 mg, and ethinyl estradiol, 0.03 mg, an ultra-low-dose oral contraceptive product, was studied in Latin America. In total, 1,206 sexually active, fertile women in their reproductive years were followed through 9,736 cycles. Only one of eight pregnancies was attributed to failure of the medication, resulting in a corrected Pearl index of 0.13. Very good cycle regulation was achieved, with an acceptably low rate of intermenstrual bleeding. The medication was discontinued for medical reasons in only 5% of the patients. Apart from a mild case of thrombophlebitis, there were no major side effects. These studies show that this combination oral contraceptive provides effective contraception with a very low incidence of side effects.