Purpose/Hypothesis: The purpose of this pilot study was to explore the influence of participant numbers during an interprofessional simulation learning experience and the students' perceptions of collaborative patient care. Number of Subjects: This study consisted of 77 pre-licensure physical therapy and nursing students over a two-year period from three academic institutions in Southwest, Virginia. Students completed the simulation experience within interprofessional teams of three (n=30) or five (n=27) students. Materials and Methods: Students were provided a patient case history to review prior to an interprofessional immersive simulation experience in an acute care environment with a standardized patient. The simulation experience consisted of a 30-minute pre-brief with an interprofessional clinical reasoning activity, a 30-minute simulation scenario, and a 30-minute debriefing. Students completed the Interprofessional Socialization and Values Scale (ISVS 21) prior to and following the experience. The ISVS measures beliefs towards collaborative practice in healthcare. Data was analyzed for each of the 21 question using frequencies. The outcomes of the two surveys (pre and post simulation) were analyzed utilizing a Wilcoxon matched pairs test. To compare the post survey responses between the two groups sizes, a Mann U Whitney test was performed. Results: Students participating in the simulation experience in the small groups of three team members demonstrated a statistically significant change (p<.002) on 18 of the 21 questions. Students in the large groups demonstrated a statistically significant change on 15 of the 21 questions. There was not a statistically significant difference between groups on the individual questions or the composite score for the ISVS. Conclusions: Interprofessional education through simulation has been shown to assist in establishing roles on a healthcare team, facilitate interaction among health professions, and encourage clinical reasoning as an interprofessional team. The optimal number of students participating in the interprofessional simulation scenarios has not been explored. This small pilot study suggests there is minimal difference between three and five participants in the simulation experience. Clinical Relevance: Although interprofessional education through simulation has been shown to be an effective technique to enhance team-based patient care, multiple barriers to the implementation of interprofessional simulation have been noted in the literature. Most notably are the potential cost, required time within the curriculum, and the optimal scheduling of the scenarios across multiple professional schools. The ability to increase the number of participants within each simulation scenario, while achieving the desired outcomes, can decrease the financial and scheduling burdens. Additional research is necessary to determine the optimal number of participants in simulation based interprofessional learning.