Hepatitis B virus (HBV) e antigen (HBeAg) seroconversion during chronic HBV infection is known to play an important role in disease progression and patient response to antiviral agents. The aim of the present study was to analyze gender disparity in distribution of major hydrophilic region (MHR) variants according to HBeAg serostatus. Prevalence of MHR variants from 68 Korean patients with chronic hepatitis (31 HBeAg-positive and 37 HBeAg-negative) was examined in terms of HBeAg serostatus and sex by direct sequencing analysis of the MHR. Gender disparity was observed in the distribution of MHR variants according to HBeAg serostatus. In male patients, the prevalence of MHR variants was significantly higher in HBeAg negative patients than in HBeAg positive patients [58.8% (10/17 patients) vs. 14.3% (3/21 patients), P = 0.004]. However, the same was not true in female patients [55.0% (11/20 patients) vs. 60.0% (6/10 patients), P = 1.000)]. In addition, 2 mutation types (L110I and G145A) related to HBeAg serostatus were found. In conclusion, HBeAg seroconversion in male chronic patients infected with genotype C could lead to mutations of MHR, major target to host immune response, which might in turn contribute to HBV persistence and immune evasion. J. Med. Virol. 83:405–411, 2011. © 2011 Wiley-Liss, Inc.