We report on the findings of an exploratory review of evidence published in English from 1945 to identify the best post-exposure prophylaxis treatment and the longest acceptable interval after exposure for prophylaxis to be effective. We found no evidence that post-exposure administration of currently available immunoglobulins is effective in preventing hepatitis A infection and disease. The use of immunoglobulins for immunoprophylaxis should not be widely recommended until a systematic review of the evidence has been conducted. We recommend that active immunization to secondary contacts of exposed and vaccinated subjects be offered.