This article proposes preliminary models for doctoral student professional identity development. It explores the question, What role do relationships play in doctoral students' professional identity development? In the first section, the author provides an overview of the prior research that informed this study with an emphasis on two previously proposed models of the doctoral student experience (Tinto, 1993; Weidman, Twale, & Stein, 2001). In the second section, the author discusses the theoretical framework that guided this research. Specifically, she describes social network theory and the connection between social (developmental) networks and professional identity development. She also includes a brief summary of socialization theory as it pertains to the first stage of the doctoral student experience. In the third section, she provides an overview of the background to the study. In the fourth section, she describes the preliminary models of doctoral student professional identity development for the two clusters of students that emerged. In the final section, she draws on the students' stories and experiences and the perspectives of their network partners (the individuals identified by the students as influential, positive and negative, throughout their first year) to generate preliminary theoretical interpretations and propositions to advance the study of doctoral education through the exploration of professional identity development while on the path to the professoriate. (Contains 2 figures and 4 tables.)