School culture is a composite of stakeholders’- employees, parents and students -perceptions of their environment. It is these perceptions and associated stakeholder behaviors which shape the dynamic culture of all schools. School success is heavily dependent on a positive, supportive school culture. This study sought to establish the role of school culture on academic performance. The study findings revealed that indeed there has been significant culture change from the time the school was managed by Catholic brothers to today when it is government managed. This change has positively affected the school performance. The study recommends that students, teachers and non teaching staff unity culture and management related cultures should be clearly defined and evaluated so that the school performance is further improved. The study is of great benefit to school management, community members and the entire ministry of education in reviving falling academic standards in many schools in Kenya.