Dissertation (MA Education)The main focus of this study was to assess the role of headteachers as internal instruction supervisors of pupils’ academic performance in Tanzania. The study used both qualitative and quantitative approaches in collecting, presenting and analyzing the data obtained from the field. The questionnaire, interview, observation and documentary review methods were used for data collection. Purposive sampling and simple random procedures were used to collect data from 63 respondents including primary school teachers, headteachers, ward education coordinators, school quality assurers and district education officers. The findings indicated that: Headteachers were not conducting instruction supervision properly and the majority were involved in some instruction activities such as checking lesson plans, schemes of work, monitoring school timetable and provide instructional materials to teachers. It was found that classroom observation, provision of feedback to teachers after classroom observation, checking of pupils’ works and monitoring of pupils’ progress reports were not conducted by head teachers in most visited primary schools. The study also found that; headteachers’ workload, lack of knowledge and skills on conducting instruction supervision, shortage of classrooms, curriculum reforms and awareness of parents on free basic education policy were the challenges which inhibit headteachers to conduct instruction supervision effectively. Moreover, the employment of more teachers, in-service training to headteachers, delegation of power to other teachers and increase the number of classrooms will lead to improvement of internal instruction supervision. The study recommends that head teachers should be provided with supervisory training for effectively internal instruction supervision. Another study could be conducted to compare instruction supervision in districts which perform better and those with poor performance.