Occupational therapy (OT) education frequently utilizes experiential learning as an effective instructional method to develop professional reasoning in OT students. However, there is little information about the development of professional reasoning. The researchers used a mixed-methods design to determine the extent to which an experiential learning course was effective in supporting professional reasoning ability with thirtysix OT students. Participants were students enrolled in an experiential learning course, which was part of their didactic graduate curriculum. Students attended an assigned setting weekly for sixteen weeks. Researchers collected data using the Self-Assessment of Clinical Reflection and Reasoning (SACRR) as well as reflective journaling. Pre-post scores on the SACRR were analyzed using repeated measures ANOVA and showed a statistically significant increase in self-perceived professional reasoning. The researchers analyzed journals from the perspective of Self-Determination Theory (SDT) using the tenets of competence, relatedness, and autonomy. Students developed professional reasoning along a continuum of competence to relatedness to autonomy. The results show that this progression does not occur in perfect stages or on a defined timeline, and provides novel insights into how the progression occurs. Occupational therapy educators can apply the results to better facilitate student development of professional reasoning. Further research could determine how to best employ SDT in OT education.