The aim of this integrative review was to identify and synthesize current evidence of factors that influence the professional identity development of nursing students in nursing educational programs. Cinahl (EBSCO), Medline, ERIC, Embase, and PsycINFO were searched. Three different appraisal tools and the PRISMA checklist were used. The data from both quantitative and qualitative studies (19 primary studies) were analyzed by applying qualitative content analysis. The analysis revealed two main themes: a caring practice–academic partnership and support in the learning environment. The following seven sub-categories were identified: clinical supervisors, ethical competence, preparation, self-confidence, predictability and safety, structure and cooperation, reflective space and safety. Our findings indicate that clinical supervisors play a central role as role models for nursing students. The main themes with sub-themes are critical in the professional identity development of nursing students in nursing educational programs.