We evaluated the immunogenicity and safety of pentavalent human-bovine reassortant rotavirus vaccine in 178 Korean healthy infants. Seroresponse rate for serum antirotavirus IgA titers was 94.7% among 94 vaccine recipients, as compared with 13.5% among 52 placebo recipients. Seroresponse rates in serum neutralizing antibody to each human rotavirus serotype in the vaccine were significantly higher in the vaccine group than in the placebo group. This vaccine was generally well tolerated and immunogenic.