This study examined how science identity and positive educational outcomes relate to student trainees' decision to pursue a research career in health-related sciences, within the context of a two-year research training program that prepares diverse undergraduate students for a research career. In analyses using the evaluation data, science identity and one of the positive educational outcomes significantly predicted trainees' decision to pursue a research career in biomedical and behavioral sciences. In general, students with stronger science identity and interest in pursuing research in academia exhibited a firmer decision to pursue a research career in sciences. In a separate analysis that examined the associations between the trainees' decision to pursue a health-related research career and their underrepresented minority identities, gender, and disciplinary track, results revealed that: (1) the interaction between trainees' disciplinary track (i.e., biomedical vs. behavioral sciences) and their total number of underrepresented minority status was associated with their decision to pursue a research career, but (2) the gender x disciplinary track interaction was not. Emphasizing the need for supporting diverse undergraduate trainees to solidify their science identity and prepare them for a research career in academia, we discuss implications of our findings for research training programs with similar aims.