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. Results: The both conflicts group had the highest odds ratios for own psychological distress and social undermining towards the partner for both genders. In addition, for husbands, the both conflicts group had the highest odds ratio for partner's psychological distress, whereas for wives, it did not. Conclusions: Dual experiences of WFC and FWC have adverse associations with psychological health of employees and relationship quality between partners of both genders. In addition, dual experiences in husbands have an adverse association with psychological health of their partners (i.e., wives), whereas this is not the case for wives.