The purpose of this study was to examine the variables explaining father`s parenting stress. Three independent variables such as sociodemographic variables, work environments and the level of involvement in childcare were included. The participants were 294 fathers who live in Seoul and Gyonggido and have their first child younger than 6 years old. The instrument used for this study were ``Paternal Involvement in Child Care Index(Radin, 1989)``, ``Parenting stress(Abidin, 1990)``, and ``Work flexibility(Seo, 1998)``. The data were analyzed using frequency analysis, descriptive statistics, and multiple regression analysis. The major results were as follows. First, most fathers reported medium level of involvement in childcare and relatively low level of parenting stress. Second, father`s parenting stress was significantly explained by type of occupations, work flexibility, work hours and level of involvement in childcare. In other words, fathers who have managerial work, less work flexibility, less work hours and less responsibility for childcare reported higher parenting stress.