Couples facing metastatic breast cancer (MBC) must learn to cope with stressors that can affect both partners' quality of life as well as the quality of their relationship. Common dyadic coping involves taking a "we" approach, whereby partners work together to maintain their relationship while jointly managing their shared stress. This study prospectively evaluated whether common dyadic coping was associated with less cancer-related distress and greater dyadic adjustment for female MBC patients and their male partners.Couples (N = 191) completed surveys at the start of treatment for MBC (baseline), and 3 and 6 months later.Cancer-related distress was assessed with the Impact of Events Scale; dyadic adjustment was assessed using the short-form of the Dyadic Adjustment Scale.Multilevel models using the couple as the unit of analysis showed that the effects of common positive dyadic coping on cancer-related distress significantly differed for patients and their partners. Whereas partners experienced slightly lower levels of distress, patients experienced slightly higher levels of distress. Although patients and partners who used more common negative dyadic coping experienced significantly greater distress at all times, the association was stronger for patients. Finally, using more common positive dyadic coping and less common negative dyadic coping was mutually beneficial for patients and partners in terms of greater dyadic adjustment.Our findings underscore the importance of couples working together to manage the stress associated with MBC. Future research may benefit from greater focus on the interactions between patients and their partners to address ways that couples can adaptively cope together.