Most students participating in science undergraduate research (UR) plan to attend either medical school or graduate school. This study examines possible differences between premed and non-premed students in their influences to do research and expectations of research. Questionnaire responses from 55 premed students and 80 non-premed students were analyzed. No differences existed in the expectations of research between the two groups, but attitudes toward science and intrinsic motivation to learn more about science were significantly higher for non-premed students. Follow-up interviews with 11 of the students, including a case study with one premed student, provided explanation for the observed differences. Premed students, while not motivated to learn more about science, were motivated to help people, which is why most of them are pursuing medicine. They viewed research as away to help them become doctors and to rule out the possibility of research as a career. Non-premed students participated in research to learn more about a specific science topic and gain experience that may be helpful in graduate school research. The difference in the reasons students want to do UR may be used to tailor UR experiences for students planning to go to graduate school or medical school.