Basic undergraduate physical activities programs play a vital role in providing undergraduates with an opportunity to develop sport related skills and healthy lifestyle habits. The effective instructional ability of the graduate teaching assistants (GTAs) who instruct a significant percentage of courses is critical to students possession of lifetime skills. The instructional ability of GTAs largely depends on the organizational culture of the program. A programs organizational culture greatly impacts the socialization and development of its members in relation to their organizational duties and responsibilities. The purpose of this study was to examine the perceptions of the organizational culture of a Research I institutions basic undergraduate physical activities program (BUPAP) from the viewpoint of graduate teaching assistants and administrators. For the purpose of this research, both qualitative and quantitative research methods and analyses were utilized. Data collection methods included: a) semistructured interviews with GTAs and administrators, b) document analysis, and c) field observations. A survey was administered to GTAs to obtain quantitative data regarding their perspectives on various aspects of the BUPAPs organizational culture. William Tierneys (1991) organizational culture framework was used to guide the study. The framework has six areas: a) leadership, b) information, c) socialization, d) environment, e) mission, and f) strategy. According to the findings of the study, the BUPAP did not take an active role in the training, development and supervision of GTAs who were instructors. Further, the GTAs developed instructional support systems that were comprised mostly of their peers and colleagues. Recommendations for improvement of the BUPAP included: a) modifying the existing selection process for graduate teaching assistantships, b) providing formal instructional supervision, c) utilizing an evaluation process that obtains multiple sources of data and d) providing more formal instructional training of GTAs. The findings from this study were consistent with previous research that suggests GTAs to be often under-trained and lack adequate instructional supervision and support.