Information concerning the student outcomes of interdisciplinary education is limited. The purpose of this study was to identify the knowledge of third-year medical students regarding the practice of certified nurse-midwives (CNMs). A 1-page survey instrument was developed and pretested. The instrument was administered as a pre- and posttest at the beginning and end of 7 Obstetrics and Gynecology rotations at 2 medical school clinical campuses of a large Midwestern medical school. Direct interaction with CNMs improved knowledge of collaborative practice arrangements and roles. This was particularly evident in knowledge areas related to CNM prescriptive authority. The medical students who had direct experience with CNMs expressed more interest in working with them in the future than those who lacked the exposure. Collaborative, interdisciplinary education of medical students appeared to promote improved understanding of roles and capabilities.