This study had two major objectives: (1) to examine the relationship between stress, social problem solving, and psychological well-being (PWB) in a sample of middle-aged adults (M 46.3 years) and (2) to examine the role of social problem solving as a potential mediator of the link between stress and PWB in this group. Correlational analyses indicated that both stress and social problem solving were significantly involved in PWB. Moreover, results from conducting a path analysis indicated that social problem solving partially mediated the link between stress and PWB. Although stress and negative problem orientation were found to be unique predictors of different dimensions of PWB, other social problem-solving dimensions also emerged as important predictors. Some implications of these findings for enhancing positive psychological functioning in middle-aged adults are discussed.