Professional service entrepreneurs (PSEs) paradoxically practice their profession in highly institutionalized contexts which require significant socialization, while at the same time enacting their role as an entrepreneur. Some activities consistent with entrepreneurship may be unnecessary for—and possibly even contradictory with— activities consistent with professional roles. In this dissertation, I addressed the questions of how two highly central role identities (professional and entrepreneurial) related to entrepreneurial orientation (EO) in professional service practices, and how EO influences performance in the context of professional practices. Using a sample of 139 physicians, I examined the relationships between the role identity centrality of two primary roles (professional and entrepreneurial) that PSEs occupy, the EO of their firms, and firm performance. This study utilized a mixed methods design, consisting of both a questionnaire and semi-structured interviews administered to a sample of professionals who own professional practice firms in the southeastern region of Florida. Findings suggest a significant and positive relationship between entrepreneurial role identity centrality and entrepreneurial orientation and a marginally significant and negative moderation of entrepreneurial role identity centrality upon the relationship between professional role identity centrality and EO. A qualitative study served to elaborate on the findings of the quantitative study, and revealed the potential of very unique understandings of the intersection of entrepreneurship and professional practice across a selection of physicians. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection