Professions generally operate within a shared set of values, symbols, and norms; in short, professions may be characterized as having somewhat unique sub-cultures. As inter-professional teamwork and collaboration gain prominence, understanding the inter-cultural dimensions of professional interactions may be useful in explaining how and why such teams function. One way of examining the unique (and common) elements of professional sub-cultures is to study the experiences of professionals who have "migrated" from one field to another. In this paper, the "culture shock" experience of pharmacists who have become physicians is described and discussed. Results from interviews with 32 pharmacist-physicians were used to frame four major themes that depict salient and unique characteristics of the cultures of pharmacy and medicine.