The western blot procedure with highly specific antipeptide antibody was applied to identify the electrophoretic mobility of hepatitis A virus capsid proteins. Polypeptides with molecular weights of 33, 29 and 27 kDa proved to be VP1, VP2, and VP3 proteins as they reacted with sera generated to VP1 recombinant protein and to synthetic oligopeptides 42-62 VP2 and 62-75 VP3, respectively.