ABSTRACT s a common belief that children will thrive if educated amongst better schoolmates, and this belief des many parents in their choice of school. Many studies have tried to measure this peer-group effect, this Research study extended literature by looking at the influence of peer group on students’ academic performance in Kasambya Sub County, Mubende District. The study was guided by the lowing objectives, to establish how peer group prior achievements influence students’ academic performance in secondary schools , to investigate how peer group composition influence student’ academic performance in secondary schools and to examine how peer learning environment influence students’ ~demic Performance secondary schools in Kasambya Subcounty, Mubende district. e study adopted a descriptive survey design with a sample size of 217 respondents comprising of 209 dents 6 class teachers and 2 Headteachers. Questionnaires were the main instrument used to collect data addition to interview guides. The data collected was analyzed using the statistical package for social ences and the final results were presented in tables for interpretation. e findings showed that majority of respondents indicated that little pocket money spend per month had a positive influence to students’ performance. It was also deduced that a rich family background positively ]uenced students’ academic performance. it was deduced that students learning environment had a si tive influence on students’ academic performance. ~e study recommends that Students and school stakeholders should be made aware of the benefits of peer up prior achievements as it greatly influences academic performance of students in secondary schools; schools administration and other stakeholders should advise the parents on the amount of money to give to ~ir children as pocket money as it has influence on the academic performance of the students in Dondary schools and lastly the School administration and stakeholders should provide good teaching and winning environment in order to achieve good academic performance. The study recommended that further search should be done in a similar topic in other counties so as to compare the study findings,