In May 2001, the U.S. Food and Drug Administration (FDA) approved Hepatitis A Inactivated and Hepatitis B Recombinant Vaccine (HEPAB) for immunization of adults. From May 2001 to September 2003, the Vaccine Adverse Event Reporting System (VAERS) received 305 reports of adverse events after HEPAB. Many events were similar to those reported after the monovalent hepatitis A and B vaccines. Non-serious events included constitutional symptoms and local reactions. Serious events included neurologic, hepatobiliary, and dermatologic conditions, and detailed medical and epidemiological review did not suggest a clear pattern of evidence supporting a causal relationship with the vaccine, except for injection site reactions and some allergic reactions.