Objective: This study intended to examine whether working mothers' job satisfaction has a moderating effect on the relationship between their parenting stress and second childbearing intention. Methods: The subjects were 202 working mothers in Seoul and Gyeonggi province, all of who had a single child under 36 months old. Working mothers' parenting stress, job satisfaction and second childbearing intention were assessed with questionnaires completed by the mothers. The data were analyzed using descriptive statistics, t-test, one-way ANOVA, Duncan test, Pearson's correlation, and moderator regression analysis. Results: First, a significant difference was revealed in the mothers' second childbearing intention depending on the type of their child's main caregiver. The second childbearing intention of the mothers who relied on babysitters to care for their children was lower than that of the mothers whose mothers, mother-in-laws or child care teachers cared for their children. Secondly, working mothers' parenting stress and job satisfaction significantly affected their second childbearing intention. Thirdly, the mothers' job satisfaction moderated the relationship between their parenting stress and second childbearing intention. Conclusion/Implications: It is necessary to provide working mothers with social support for enhancing their job satisfaction and alleviating their job stress, in order to increase their second childbearing intention.