In Korea, the youth are highly vulnerable to hepatitis A virus (HAV) infection. This study was aimed to investigate the acceptance of HAV vaccination among mothers and its influencing factors in children and adolescents\' HAV vaccination. We performed telephone-based survey with a nationally representative sample (n= 800) of mothers of children and adolescents aged 7-18 years in 2013. It was conducted by using a random-digit dialing method for household telephone numbers along with the research panel of Hankook Research (Seoul, Korea). Descriptive statistics, univariate and multiple logistic regression were used to find the factors associated with not willingness. Sixty eight percent of mothers were willing to vaccinate their child with current cost and 91.8% if the cost lowered to half. The level of mothers\' awareness of severity of HAV infection was high whereas their recognition of vaccine’s benefit was moderate. The perception of susceptibility/severity of HAV infection and that of benefits/barriers of HAV vaccination were significantly associated with mothers\' willingness to vaccinate their child. Under the current cost, mothers with residence in rural area, low monthly household income, increase in number of children, having no overseas travel experiences of family members, and having no plan for their child to go abroad have a higher proportion of mothers with not willing to vaccinate their child. In multivariate logistic regression analysis, increase in number of children (n≥3) and having no plan for their child to go abroad were negatively influencing factors on willingness to vaccinate with current cost (odds ratio [OR]: 2.85; 95% confidence interval [CI]: 1.66-4.89 and OR: 2.71; 95% CI: 1.97–3.74, respectively). Nonresponse to the question of income had higher odds for not accepting HAV vaccination compared to high income more than $2,700 monthly (OR: 1.90; 95% CI: 1.01–3.58). With half the cost, similarly the same factors were also significantly associated with mothers\' willingness to vaccinate their child except the number of children. Korean mothers generally have positive cognition of HAV vaccine, but cost of the vaccine appears to be an important barrier. Financial support and information about the necessity of HAV vaccination in Korea would help improve the mothers\' acceptance.