Objectives. A growing body of evidence suggests that provider decision making contributes to racial/ethnic disparities in care. We examined the factors mediating the relationship between patient race/ethnicity and provider recommendations for coronary artery bypass graft surgery. Methods. Analyses were conducted with a data set that included medical record, angiogram, and provider survey data on postangiogram encounters with patients who were categorized as appropriate candidates for coronary artery bypass graft surgery. Results. Race significantly influenced physician recommendations among male, but not female, patients. Physicians' perceptions of patients' education and physical activity preferences were significant predictors of their recommendations, independent of clinical factors, appropriateness, payer, and physician characteristics. Furthermore, these variables mediated the effects of patient race on provider recommendations. Conclusions. Our findings point to the importance of research and intervention strategies addressing the ways in which providers' beliefs about patients mediate disparities in treatment. In addition, they highlight the need for discourse and consensus development on the role of social factors in clinical decision making.