Abstract: The purpose of this study is to determine the influence of head teachers’supervision of curriculum implementation on pupils’ performance in Kenya Certificate of Primary School in public primary schools in Meru County. Descriptive survey research design was adopted and a sample of 65 head teachers, 389 teachers and 778 pupils was drawn from 65 public primary schools in Meru County. The instruments used were the questionnaires for head teachers and teachers while focus group discussion was applied to collect data from the pupils. The data was presented in frequencies, mean and percentages. The study found out that most of the head teachers were too busy with administrative duties and this made them fail to supervise teachers as they carried out their duties and this significantly influenced pupils’ performance in KCPE. This study recommends that the Directorate of Quality Assurance organize more capacity building for head teachers on management to equip them with managerial skills necessary to schools for academic excellence.