This study sought to investigate the principals’ management of teachers’ workload pressure and students’ academic performance in public day secondary schools in Kitui West sub-County. The study objective sought to establish the influence of Principals’ teacher workload management practices on students’ academic performance. The study was based on Job Demands–Resources theory whose characteristics can be categorized into two major groups which include job demands and job resources. Descriptive survey research design was used in the study. The study target population included all the 26 principals and 249 teachers. Census and systematic sampling techniques were used to select a sample of 26 principals and 38 teachers respectively. Questionnaires were used as data collection tools. Data was analyzed qualitatively and quantitatively using descriptive statistics. Frequency distribution and cross tabulation tables were used to present data. Qualitative data was analysed organized in subthemes and analysed qualitatively based on research objectives and presented in a narrative form. The study found that on average majority 83.7% of the principals and 74.8% of the teachers respectively were in agreement with the statement that the management practices of teacher workload pressure influences students’ academic performance. The study recommends ensuring adequate staffing in schools by the Teachers’ Service Commission to curb overworking teachers and promotion of teamwork for better academic performance. This study may be significant in that the research outcomes could inform policy formulation in the Ministry of Education regarding principals’ work environment management. The findings contribute to existing knowledge and serve as a basis for future research. The study advances conceptual understanding and provides empirical evidence in educational leadership and organizational behavior in relation to teacher workload management practices. The study concluded that principals’ management practices can significantly impact on students’ academic performance.