Being discriminated against is an unpleasant and stressful experience, and its connection to reduced psychological well-being is well-documented. The present study hypothesized that a sense of control would serve as both mediator and moderator in the dynamics of perceived discrimination and psychological well-being. In addition, variations by age, gender, and race in the effects of perceived discrimination were explored. Data from the Midlife Development in the United States (MIDUS) survey (N = 1,554; age range = 45 to 74) provided supportive evidence for the hypotheses. The relationships between perceived discrimination and positive and negative affect were reduced when sense of control was controlled, demonstrating the role of sense of control as a mediator. The moderating role of sense of control was also supported, but only in the analysis for negative affect: the combination of a discriminatory experience and low sense of control markedly increased negative affect. In addition, age and gender variations were observed: the negative impact of perceived discrimination on psychological well-being was more pronounced among younger adults and females compared to their counterparts. The findings elucidated the mechanisms by which perceived discrimination manifested its psychological outcomes, and suggest ways to reduce adverse consequences associated with discriminatory experiences.Recent studies have repeatedly demonstrated that the experience of being treated unfairly or discriminated against is associated with reduced mental health (e.g., Barnes, Mendes de Leon, Wilson, Bienias, Bennett, & Evans, 2004;Kessler, Mickelson, & Williams, 1999;Noh, Beiser, Kaspar, Hou, & Rummens, 1999;Williams, Yu, Jackson, & Anderson, 1997). Discrimination may result from a variety of factors including age, gender, race, ethnicity, sexual orientation, physical appearance, and social class (Carr & Friedman, 2005;Williams et al., 1997). Whatever the source, perceived discrimination is known to contribute to the higher rates of psychological distress found among socially disadvantaged populations (Kessler et al., 1999;Thoits, 1983). Based on a large-scale national survey from the Midlife Development in the United States (MIDUS) study, Kessler and colleagues (1999) found that a surprisingly high proportion of the U.S. population (61%) reports experiences of discrimination in their daily life. Despite such evidence, there remains a paucity of research addressing perceived discrimination as a life stress and examining the intervening factors for this stressor (Dion, 2002;Kessler et al., 1999;Thoits, 1983). The pervasiveness of discriminatory experience and its adverse psychological consequences call attention to further research on the issue of discrimination. The present study explored the dynamics of perceived discrimination and psychological wellbeing, with a focus on sense of control. Sense of control refers to the extent to which individuals perceive that they have personal power and control over their life and environment ...