Abstract INTRODUCTION HIVincidence estimates are essential to monitor the progress of prevention and control interventions. METHODS Data collected by Brazilian surveillance systems were used to derive HIVincidence estimates by age group (15-24; 25+) and sex from 1986 to 2018. This study used a back-calculation method based on the first CD4 count among treatment-naïve cases. Incidence estimates for the populationaged 15 years or over were compared to Global Burden of Disease Study (GBD) estimates from 2000 to 2018. RESULTS Among young men (15-24 years), HIVincidence increased from 6,400 (95% CI 4,900-8,400), in 2000, to 12,800 (95% CI 10,800-15,900), in 2015, reaching incidence rates higher than 70/100,000 inhabitants and an annual growth rate of 3.7%. Among young women, HIVincidence decreased from 5,000 (95% CI 4,200-6,100) to 3,200 (95% CI 3,000-3,700). Menaged ≥25 years and both female groups showed significant annual decreases in incidence rates from 2000 to 2018. In 2018, the estimated number of new infections was 48,500 (95% CI 45300-57500), 34,800 (95% CI 32800-41500) men, 13,600 (95% CI 12,500-16,000) women. Improvements in the time from infection to diagnosis and in the proportion of cases receiving antiretroviral therapy immediately after diagnosis were found for all groups. Comparison with GBD estimates shows similar rates for men with overlapping confidence intervals. Among women, differences are higher mainly in more recent years. CONCLUSIONS The results indicate that efforts to control the HIVepidemic are having an impact. However, there is an urgent need to address the vulnerability of young men.