Altruistic dentists play a central role in treating minority populations, the poor, the uninsured, and those living in underserved communities. This study examines factors associated with graduating dental students' altruistic attitudes. We use a nationally representative dataset, the 2007 American Dental Education Association Survey of Dental School Seniors (n=3,841), and a comprehensive framework to investigate individual, school, and community characteristics that may influence altruism. Student characteristics were the most significant predictors: women, African Americans, Hispanics, Asian/Pacific Islanders, and students with low socioeconomic status expressed greater altruism than their counterparts. These results inform dental educators and administrators to expand efforts to recruit underrepresented racial/ethnic and low-income students into dentistry. Additionally, we found that students with altruistic personalities attend schools where the social context is more accepting and respectful of diversity. This suggests that schools can promote altruism in their students by creating a positive culture and environment for diverse populations.