The purpose of this study was to identify factors that influence the development of critical thinking skills of student nurses from entrance to exit in an associate degree in nursing program. Three research questions guided this study: (1) What pedagogical factors influence the development of critical thinking skills from entrance to exit for students in an associate degree in nursing program? (2) What personal factors influence the development of critical thinking skills? (3) What other factors influence the development of critical thinking skills? A qualitative research approach was implemented with a purposive sampling of ten graduates from an associate degree in nursing program who had increased their critical thinking skills substantially, as measured by the Critical Thinking Assessment developed by Assessment Technologies Incorporated. In-depth, semi-structured interviews were done with the ten graduates looking at their perceptions of the factors that increased their critical thinking skills during the nursing program. This study found that the pedagogical factors that influenced the development of critical thinking skills were curriculum design and integrative learning activities. Curriculum design was further broken down into acquiring foundational concepts, progressing from simple to complex concepts, and applying learning in the clinical area. The subcategories of integrative learning activities included tests, case studies, simulations, and care maps. The biggest surprise in this area was that all of the participants mentioned testing as a factor that improved their critical thinking skills. Personal factors identified were curiosity, confidence, and perseverance. Other factors included faculty support and reinforcement in and out of the nursing program. Three conclusions were drawn from this study. First, curriculum design is a key factor in promoting critical thinking. Second, personal characteristics promote the development of critical thinking. Finally, reinforcement promotes the development of critical thinking. Practice implications and recommendations for future research were also provided.