Compared to White individuals and men, Black individuals and women demonstrate a lower tolerance for experimental pain stimuli. Previous studies suggest that pain catastrophizing is important in this context, but little is known about which components of catastrophizing contribute to these race and sex differences. The purpose of the current study was to examine the individual components of catastrophizing (rumination, magnification, and helplessness) as candidate mediators of race and sex differences in experimental pain tolerance. Healthy undergraduates (N=172, 74% female, 43.2% Black) participated in a cold pressor task and completed a situation-specific version of the Pain Catastrophizing Scale. Black and female participants demonstrated a lower pain tolerance than White (p<0.01; d=0.70) and male (p<0.01; d=0.55) participants, respectively. Multiple mediation analyses indicated that these race and sex differences were mediated by the rumination component of catastrophizing Perspective: This study suggests that differences in pain-related rumination, but not magnification or helplessness, are important contributors to race and sex differences in the pain experience. Interventions that target this maladaptive cognitive style may help reduce disparities in pain.