Monitoring trends of contraceptive use and identifying the groups with less coverage are needed to guide public policies and make them more efficient. But, in Brazil, recent data about these aspects are limited. This study aimed to investigate the prevalence of contraceptive use and its inequalities during adolescence and early adulthood. Data from the 1993 Pelotas birth cohort, Rio Grande do Sul State, Brazil, were used. At 15, 18 and 22 years, respectively, 335, 1,458 and 1,711 women reported having started their sexual lives and were included in analysis. Prevalence and 95% confidence intervals were obtained to describe the most used contraceptive methods. Inequalities in modern contraceptive use were evaluated according to wealth index, scholastic backwardness and ethnicity. In all follow-ups, more than 80% of women used at least one modern method. The use of barrier methods decreased with age; at 22 this prevalence was 36.3%. Such use concomitant with other modern methods was lower than 50% in all follow-ups. We observed inequalities in the use of modern contraceptive methods, mainly in barrier methods used with other modern methods. These findings may contribute and improve the public policies in family planning.