This study sought to establish the influence of the status, utilization and management of physical and instructional resources on the academic performance of students in Public Secondary Schools in Nandi East Sub- County. The study was conducted in six Public Day Secondary Schools. Purposive sampling was used to identify the respondents. Systems Theory and Resource Based Theory guided the study. The research instruments included questionnaires, interviews and observation. Data was analyzed by use of descriptive (Frequencies, Means and Standard Deviations) and inferential statistics (Analysis of variance- ANOVA and Kruskal-Wallis). The findings showed that the schools did not have adequate physical and instructional resources and what was available was not put to maximum use; management of the resources was not in compliance with the standards set by the Ministry of Education Science and Technology, especially the preventive and emergency maintenance. There was significant difference in the use and management of physical and instructional resources classified among the fair performing, poor performing and the very poor performing schools. In all the cases the p value 0.00 was less than the set Alpha (p<0.05).The study recommends thatthe schools should invest more in physical and instructional resources; improve the extent of use of the physical and instructional resources particularly, laboratory equipment, playground, first Aid kit, library; models, maps, computers, charts, text books; and manage the physical and instructional resources according to standards set by the Ministry of Education Science and Technology.