The present study examined the relationship between the two central dimensions of perfectionism, Pure Personal Standards (PPS) and Maladaptive Evaluative Concerns (MEC), and psychological distress as well as positive affect. The study also explored two potential mediators, self-concealment (SC) and contingent self-worth (CSW), of the relationship between these perfectionism dimensions and various mental health measures. Participants completed questionnaires assessing perfectionism, the two mediator variables, and a number of measures of mental health, including depression, fear of negative evaluation, positive affectivity, and eating disorder symptomatology. Analyses revealed that extracting out the MEC from PPS perfectionism scores using partial correlations removed the one significant correlation of PPS with psychopathology, and strengthened its positive correlation with well-being. In contrast, the MEC dimension of perfectionism was positively related to psychopathology and negatively related to well-being, even when controlling for PPS scores using partial correlations. Mediational analyses indicated that CSW significantly mediated the relationships between PPS and mental health, including fully mediating the relationship between PPS and each measure of psychopathology. Multiple mediational analyses revealed that SC and/or CSW mediated the relationships between MEC and mental health indices. These findings suggest that the central aspect of perfectionism related to psychopathology is the MEC dimension whereas PPS is more closely associated with positive features of mental health. Findings also suggest that future investigations of the relationship between perfectionism and psychopathology take into consideration the mediating effects of SC and CSW.