There is evidence that positive and negative social exchanges have different implications for various psychological outcomes, but research has been limited by a lack of multidimensional and parallel measures and underlying processes explaining the implications are not well understood. In the present longitudinal study, we address these gaps in the literature by using parallel measures of positive and negative social exchanges to predict both positive and negative aspects of emotional health in a sample of 113 first-year college students and by testing for loneliness as a mediator. Consistent with a domain-specific effects model, increases in negative exchanges were associated with increases in negative but not positive emotional well-being and vice versa. Changes in loneliness partially mediated these effects.