The purpose of this study was to find out the effects of team building on academic performance by public secondary schools in Rarieda Sub-County. The objectives of the study were to: determine the team building activities used by public secondary schools in Rarieda Sub-County; determine academic performance of public secondary schools in Rarieda Sub-County and to find out the effects of team building on academic performance in National Examinations by public secondary schools in Rarieda Sub-County. The study summarized the findings in line with the objectives. The study found a significant positive relationship between team building and academic performance in National Examinations. The study concluded that high level of usage of team building positively affect academic performance in National Examinations. The study recommended emphasis on team building in the management of schools.