In an exploration of the links between relationship quality and depression, the extent to which women’s weekly reports of depressive symptoms vary as a function of same-week relationship functioning was tested. A sample of 161 married or cohabiting U.S. women completed measures of relationship functioning, mood, and depressive symptoms weekly for 12 weeks. In a series of hierarchical linear models, results of within-subject analyses indicated that depressive symptoms were negatively associated with same-week relationship functioning. Weekly fluctuations in mood did not account for these associations. Results of between-subjects analyses suggested that women low in stereotypical masculinity and in relationships of shorter duration are particularly likely to show increased depressive symptoms during weeks when they experience poorer relationship functioning than usual.