The prevalence of markers for hepatitis B virus (HBV) and the rate of compliance with HBV vaccination laws were investigated in a study at Padua University Medical School (Italy). Of 2,361 students, 385 (16.3%) tested negative for antibody to hepatitis B surface antigen. When vaccination was actively offered to these students, there was a low rate of compliance (47.0% [181 students]) but a good rate of seroconversion (93.1% [95 of 102 students]). Screening for HBV markers appears to be crucial to efforts to increase rates of vaccination coverage.