Despite interventions by policymakers and implementers in instituting BOM so as to ensure the delivery of quality education in Kenya, performance in some schools has remained poor. According to the Sub County director of education, Kisii has witnessed very poor performance in the Kenya Certificate of Secondary Education (KCSE) examination over the years. To address the situation, the Kisii Central County Education office conducted workshops to capacity-build the BOM members from the entire County in relation to their roles in schools. It was for this reason that the study was to establish the influence of board of management practices on students’ academic performance in public secondary schools of Kisii Sub County. The study adopted a descriptive survey design. The target population consisted of 53 public secondary schools in Kisii Central Sub County with 53 principals, 391 teachers, 689 members of the Board of Management, and 14,776 students. The sample size comprised 44 secondary school principals, 44 assistant teachers, 42 students and 248 members of the Board of Management. This constituted a total sample size of 378 respondents. Data was collected through self-administered questionnaires as well as through interview schedules for the BOM members. A pre-test of the instruments was conducted in three schools using 38 respondents constituting 10% of the study sample. Quantitative data was analyzed using descriptive statistics (frequency counts, the mean, and standard deviation) and inferential statistics (correlation) by employing SPSS version 21.0 and excel computer packages. Qualitative data was organized into themes, and categories as they emerged from the field and presented in narrative form. The analysis of results revealed that teaching and learning resources, staff recruitment and incentives positively and significantly influence the academic performance of students in secondary school. The study recommended that in order to improve the academic performance of students in secondary schools, the BOM should ensure that they provide enough teaching and learning materials to schools to guarantee the performance of students in their academics, recruit competent teachers to improve the teacher-student ratio which is a necessary measure in improving the performance of students in academics, establish the most appropriate method of appreciating teachers and students so as to motivate them to work positively toward improving the academic performance of students