We examined the relationship between sense of professional identity and academic success among under-represented minority graduate students in a biomedical doctoral program. We found that a sense of professional identity is related to science success among under-represented minority students, but not for non-underrepresented minority students. Sense of professional identity appears to be linked to the use of mentors and to development as a scientist and member of the professional community, rather than someone who simply performs laboratory experiments. (Contains 2 tables.)