The aim of this study was to explore dental students' attitudes about treating populations that are low-income rural, non-white, and with special needs. All 259 students in all four years at one U.S. dental school were invited in January 2018 to participate in a survey with questions about treating these three populations in the following areas: personal value, perceived preparedness, comfort, future intent to treat, and professional responsibility. A total of 227 students completed the survey, for an overall 87.6% response rate. By class, participants were as follows: D1 n=63, 100% response rate; D2 n=60, 98.4% response rate; D3 n=67, 98.5% response rate; and D4 n=37, 53.6% response rate. The results showed that dental school class did not predict willingness to treat the specified populations. Regarding populations that are rural and non-white, personal value and professional responsibility significantly correlated with intent to treat. Women perceived stronger professional responsibility regarding treatment of populations that are low-income rural (M=1.97, SD=1.09; p=0.004) and non-white (M=1.95, SD=1.07; p=0.013) than did men (M=2.44, SD=1.23; M=2.34, SD=1.22, respectively). More advanced students reported greater preparedness regarding populations that are rural and non-white, but not patients with special needs. Preparedness correlated with intent to treat for patients with special needs only. Women were less comfortable than men in treating patients with special needs (χ2=6.10, p=0.014). Hometown residence had a limited effect for patients with special needs only. Rural residence did not predict students' attitudes about serving rural patients. Overall, the students reported positive intentions to serve populations that are low income, but showed less confidence and willingness in treating patients with special needs, especially among women. These results suggest that the students' comfort in serving patients with low income was more static and less malleable than preparedness. As preparedness and personal value were positively correlated, students may have found worthwhile what they felt prepared to do.