The paper discuses the infuence of head teachers' competencce o pupils' performances in KCPE. The reasearch objectives were: to estabilish the extent to which head teachers' academic and professional qualifications, work experience aid involvement of staff in management of school fasilities influence pupils' performance in KCPE. The study employed escriptive survey design. The school selected were 14 from WestLand and Dagoretti districts and 13 from lang'ata district through simple random sampling. The 41 head teachers and 41 senior teachers from each school were selected by census. The research instrument used were the two sets of questionnaires for the head teachers and senior teachers. validation of both instrument was done by the expert judgement review by supervisor from the Departement of Eduacational Administation and planning of the University of Nairobi. The reliability coefficient of the research instruments was determined by split-half method, and was found to be 0.73 and 0.88 for the head teachers' and senior teachers' questionnaires respectively. Descriptive statistics were used to analyze the data which was presented in tables. The findings were: the head teachers with high academic and professional qualifications, long work experience ang involvement of staff in management of school facilities enhanced positively the pupils' performance in KCPE. Therefore, the competence of head teachers influenced positively the pupils' performance in KCPE. The following recommendeations were suggested: Ministry of Education, Science and technology should provide adequate funds for in service traingn of head teachers to promote their competence and Kenya Education Management institute should encourage head teachers to parcitipate in a curriculum on managemnt for head teachers by subsiding costs. This will enchance head teachers' competence.