Education is fundamental human right and a key input in production and development of an economy. Education in schools is determined by provision of resources, their maximum utilization and management. School resources such as libraries, computers, laboratories, textbooks, charts ,maps among others have a great impact on academic performance of students. Inadequate resources translate to poor performance. The purpose of this study was to investigate effects of inadequate teaching and learning resources on student academic performance in public secondary schools in Meru south sub county Tharakanithi county Kenya. The objectives of the study were ; to find out how the availability of learning resources used by students influence their performance,to investigate the availability of supportive equipment in public secondary schools in Meru south sub county,to ascertain the availability of teaching resources used by teachers. The study used descriptive survey design and data was collected using three sets of questionnaires one for teachers , principals and the other for students. The data was analyzed using descriptive statistics, which helped summarize and interpret the collected information to identify patterns and trends. Measures such as percentages, frequencies,charts were used The study population comprised of 2100 respondents.The questionnaires were returned by only 230 respondents out of the 336 sampled. Although most schools had libraries, laboratories and classes most of them were regarded to be in poor condition.Data was analyzed using descriptive survey design using statistical package for social sciences (SPSS).The analyzed data was then be presented using frequency tables. The study found out that most teaching and learning resources like textbooks were adequate, library materials laboratory equipment were fairly adequate.The study established that absence of adequate teaching and learning resources hinder students to perform well.Teachers also had difficulty in planning and delivering lessons and inability to conduct practical experiments.Inadequacy of resources also impact student learning negatively by lowering students’ engagement and participation in class