Effective interprofessional collaboration between nurse practitioners and physicians is imperative to meet the health care needs of all Americans. This project measures attitudes of nurse practitioners to determine the barriers to effective interprofessional collaboration with their physician colleagues. It was hypothesized that there is a positive relationship between nurse practitioner attitudes and interprofessional collaboration and a positive relationship between years in practice and interprofessional collaboration. Sixty-three nurse practitioners participated by completing the Collaborative Practice Scale and Jefferson Scale of Attitudes toward Physician and Nurse Collaboration. The Core Competencies for Interprofessional Collaborative Practice served as the framework for this project. Findings of this project revealed nurse practitioners are overall accountable for their patient care and report high levels of interprofessional collaboration. These results are a foundation for future inquiry in providing and evaluating programs to enhance interprofessional collaboration.