We conducted a cross-sectional seroprevalence study to determine hepatitis B vaccination coverage and hepatitis B virus (HBV) immunity in a population of young adult males. Specifically, the population is comprised of Air Force conscripts from the metropolitan region of Florianópolis, Santa Catarina, South Brazil, who were born prior to the full implementation of the HBV vaccination program. Of the 371 young males surveyed, 90% received at least 1 dose of the vaccine and 84% completed the 3-dose schedule. Overall, 57% had positive anti-HBs titers. We must continue to vaccinate individuals up to 20 years of age in order to guarantee a significant reduction in cases of hepatitis B virus.