The long-term efficacy of hepatitis B vaccination among high-risk infants was determined in 805 vaccine responders, immunized at birth in Taiwan during 1981-1984 and followed to age 10 years, via life table survival and Cox multivariate analyses. At 10 years, cumulative persistence of antibody to hepatitis B surface antigen (anti-HBs) was 85%, and cumulative incidence of hepatitis B virus (HBV) infection was 15%. Three children became carriers. Twelve-month anti-HBs titer was the strongest predictor of efficacy. The higher the initial titer, the lower the risk of anti-HBs loss (relative risk [RR], 0.26 for titer of 100-999 mIU/mL; RR, 0.08 for titer >1000 mIU/mL; P<.001) and HBV infection (RR, 0.55 and 0.27; P<.05). Maternal hepatitis B e antigen positivity but not hepatitis B immunoglobulin dose or gender predicted greater antibody persistence to age 10 years. Because the level of antibody persistence remained high and few became carriers, booster revaccination within 10 years seems unnecessary.