Addressing a previous gap in the gerontological literature, the present study examined the effects of both positive and negative social exchanges within key relationships (spouse, children, and other relatives/friends) on the depressive symptoms of younger (28 to 59 years old) and older (60 to 92 years old) men and women. Separate analyses were carried out on younger adults (N = 452) and older adults (N = 849) who were respondents in the Americans' Changing Lives study. In both age groups, positive and negative social exchanges with the same source were significantly (p < .001), inversely related (rs range from -.23 to -.43); and positive social exchanges exerted stronger net effects on depressive symptoms than negative social exchanges. For older adults, some buffering effects were found when negative and positive social exchanges were associated with different sources; for younger adults, buffering effects were found when negative and positive social exchanges were associated with the same source. These buffering effects were not conditioned by gender. The findings of the present study highlight the importance of taking into account the age of the recipient and the provider-recipient relationship when studying the joint influence of negative and positive social exchanges on adults' depressive symptoms.