Functional cure is an essential endpoint in the management of patients with chronic hepatitis B virus (HBV) infection. We evaluated the cumulative probability and predictors of functional cure in patients with chronic HBV infection after hepatitis B e antigen (HBeAg)-seroconversion. We retrospectively analyzed 413 (249 males and 164 females) initially HBeAg-positive chronic HBV-infected patients, who were followed up for a mean of 26.36 ± 0.53 years. All underwent HBeAg-seroconversion during follow-up. A functional cure was defined as durable HBsAg and HBV DNA loss without antiviral treatment for more than 24 weeks. After 10,888 person-years of follow-up, the cumulative probability of functional cure was 14.53% (n = 60). There were 24 (40%) subjects with functional cure after antiviral therapy. The annual functional cure rate was 0.55% per perperson-year, and increased to 0.96% per person-year after HBeAg-seroconversion. In subjects with functional cure, the HBsAg and HBV DNA titers after HBeAg-seroconversion were positively correlated with the time to functional cure (P < .001 and < .001, respectively). Multivariate Cox proportional hazard analysis of the cohort revealed that HBeAg-seroconversion at < 18 years of age, high genetic barrier nucleos(t)ide analogue(s) therapy before HBeAg-seroconversion, and a serum HBsAg titer < 1,000 IU/mL at 18 months after HBeAg-seroconversion were significant predictors of functional cure (P < .001, .001, and .001, respectively). In a cohort of chronic HBV-infected patients with long-term follow-up, HBeAg-seroconversion in childhood, high genetic barrier nucleos(t)ide analogue(s) therapy, and low HBsAg titers after HBeAg-seroconversion were significant predictors of functional cure.