PURPOSE: The study was done to investigate factors in mothers related to their intention to get additional vaccination for their children aged 4~6 years. METHODS: A descriptive correlational study was conducted. The participants were 858 mothers conveniently selected from a public health center in Seoul. Data were collected using self-administered questionnaires. Descriptive statistics, t-test, ANOVA, correlation and stepwise multiple regression were used for data analysis. RESULTS: The mothers got a high of 2.08 marks on intention to get additional vaccination. The intention was positively correlated to attitude, perceived benefits, self-efficacy and negatively to perceived barriers, parenting stress. The most significant variables was attitude, perceived benefits, self-efficacy and those three variables explained 42.7% of mother's intention for additional vaccination. CONCLUSION: The above mentioned findings were identified as significant factors affecting mother's intention for additional vaccination. The findings are expected to make a positive contribution to creating an ideal intervention and to promoting an increased vaccination rate.