Context: Simulation is a frequently used technique for interprofessional education, allowing students from multiple professions to work together in providing quality patient care. However, little is known about the impact of interprofessional simulation with the inclusion of athletic training students because of the lack of literature. Objective: This study explored the impact of an interprofessional simulation on athletic training, nursing, and occupational therapy students' attitudes toward interprofessional collaboration after participation in an interprofessional simulation. Design: Quasi-experimental mixed-methods study, using a single-group, pretest-posttest design. The quantitative results are reported here. Setting: Private mid-sized Midwestern university. Participants: Seventy-nine students, representing athletic training, nursing, and occupational therapy, participated in the simulation; 32 of these students completed pretest/posttest questionnaires. Intervention: Students in all professions cared for or observed the care of a standardized patient from the time of a spinal cord injury on the football field through an ambulance ride and subsequent emergency and inpatient care. Students completed pretest/posttest questionnaires in the week before and immediately after the simulation. Main Outcome Measure: The Jefferson Scale of Attitudes Toward Interprofessional Collaboration (JeffSATIC) measured attitudes toward interprofessional collaboration. It consists of 2 subscales: Accountability and Working Relationships. Higher scores indicated more orientation toward teamwork and collaboration. Results: Participants demonstrated significant change on the JeffSATIC's Working Relationship subscale (P = 0.003). The Cohen d effect size was calculated for presimulation and postsimulation change, which showed a medium effect for the overall scale (d = 0.46), a negligible effect for the Accountability subscale (d = 0.02), and a large effect for the Working Relationship subscale (d = 0.79). Conclusions: This study demonstrates the utility of the simulation in improving attitudes toward interprofessional working relationships. Further research should explore the differences noted between athletic training students and other health care profession students.