PURPOSE: The objectives of this study are to evaluate the significance of HBeAg positivity in infants born to HBeAg and HBsAg positive mothers. METHODS: The HBeAg status of 22 HBeAg positive, HBsAg negative infants born to HBeAg and HBsAg positive mothers from December 1996 to March 1999 were evaluated by enzyme immunoassay. RESULTS: The number of HBsAg positive carrier mothers was 213(4.9%) out of 4,338 pregnant women. HBeAg was positive in 76(41.5%) out of 183 HBsAg positive mothers. Only 49 infants born to 76 HBeAg positive mothers could be evaluated; 36 infants were HBeAg positive and HBsAg negative. Laboratory follow up was possible in 22 infants. HBeAg disappeared in 7 cases within two months and in 20 cases within 12 months(over 90%). Ultimately, twenty-two babies who were HBsAg-negative and HBeAg-positive became negative for HBeAg, however, one showed HBsAg in follow up of 6 months of age. CONCLUSION: HBeAg positivity in infants born to HBeAg positive mothers may result from the maternofetal transmission and this HBeAg eventually disappeared without clinical significance.