Objectives: This study among Japanese dual-earner couples examined the independent and combined associations of work-to-family conflict (WFC) and family-to-work conflict (FWC) with psychological health of employees and their partners and the relationship quality between partners. Methods: The matched responses of 895 couples were analyzed with logistic regression analysis to examine whether there were differences among the four work-family conflict groups (i.e., no conflict, WFC, FWC and both conflicts groups) in terms of own psychological distress, social undermining (i.e., negative behaviors directed toward the target person) reported by partners and partner's psychological distress. The no conflicts group was used as the reference group....