Injecting drug users (IDUs) are at high risk for contracting and spreading viral hepatitis through nonsterile injection practices, unprotected sexual contact, and unsanitary living conditions. We sought to characterize hepatitis knowledge, prior testing, and vaccination history among IDUs at a New York City syringe exchange program (SEP). IDU subjects generally had a poor understanding of viral hepatitis transmission and prevention. We also found low vaccination rates: only 8% reported receiving hepatitis A vaccine and 11%, hepatitis B vaccine. Educating IDUs about risky behaviors and medical preventive interventions, such as vaccines for hepatitis A and B and treatment for hepatitis C, may help prevent disease and reduce transmission. Stronger linkages between health-care centers and SEPs, drug treatment programs, and other service delivery centers where IDUs are encountered may promote hepatitis education and vaccination.