The purpose of this study was to examine the knowledge that a physical education teacher possesses and how the knowledge was constructed. Three middle school physical education teachers served as key participants in this study. Data were collected by interviews, field notes, personal communication via E-mail and telephone, and a focus group meeting. Three individual case narratives were compiled based on the emergent themes. Additionally, a cross-case analysis compared similarities and differences among the participants. The results indicated that teachers utilize common sources of knowledge, yet construct their knowledge uniquely. The primary sources from which a teacher sought knowledge differed depending upon the experience of the teacher.