Purpose: This study examined the effects of job stress on parenting. Specifically, we examined the short-term effects of daily negative emotion at work on emotions and parenting behaviors at home. The concept of family system was applied to explore not only spillover effects, but also crossover effects. Methods: A total of 32 paired working fathers and mothers with their preschoolers participated in this study. Survey-type dyadic daily diaries were used to collect data over 5 days. Negative emotion from daily work, home negative emotion, and parenting behaviors were recorded to examine the short-term effects of work stress on parenting. Data from 22 pairs with no missing data on the 5-day records were used for further analyses using multivariate hierarchical linear modeling. Results: In sum, the mothers' level of home negative emotions, and of supportive and restrictive parenting was higher than fathers'. Fathers' home negative emotions were affected by their own and their spouses' work negative emotions. Mothers' work negative emotions affected fathers' supportive parenting behaviors. Conclusions: The spillover effect and crossover effect of work stress on parenting occurred with fathers, but not mothers. When examining both work and home negative emotions, mothers' supportive parenting behaviors were affected by their own and their spouses' home negative emotions. Gender differences in work and family roles, emotional states, and behaviors after emotional arousal are discussed.