This paper outlines the initial findings of an action research project that focuses on the possible contribution of peer observation to a more collaborative environment and teachers' professional growth at The University High School. The research component played a significant part as previous attempts to change the culture at the school were unsuccessful and investigating the forces that prevent collaboration in the day-to-day workings of the school became necessary. Our investigation reveals that whilst a peer observation programme has great potential to stimulate cooperation amongst teachers, the ingrained power relations in schools turn its intended professional growth outcomes on its head. Only if the school's leadership employs strategies to counter entrenched disciplinary structures in schools, can peer observation lead to more collaboration between staff members and stimulate professional learning. (Contains 2 figures and 2 tables.)