This study was conducted to examine the extent to which heads of schools’ coach teachers to improve their professional development in community public secondary schools in Simanjiro District, Tanzania. The study was guided by the theory of Total Quality Management (TQM). The study employed convergent research design under the mixed methods research approach. The target population in this study included teachers of community public secondary schools, heads of schools and the District Secondary Education Officer. The study sample comprised of 73 respondents in which 60 teachers were sampled through stratified and simple random sampling technique. Questionnaires and interview guides were used to collect the required data. The reliability of quantitative instruments was established through Cronbach Alpha. The validity and reliability of qualitative instruments was established through triangulation method. Quantitative data were analysed by using descriptive statistics such as frequencies, means, and percentages and presented in tables with the aid of Statistical Package for Social Science (SPSS) version 23. The qualitative data were analysed by developing themes from research questions and present them in narrative form and direct quotations. The study found out that to a small extent heads of schools perform coaching role since they have inadequate coaching knowledge which is caused by the lack of training, seminars or workshops to heads of schools. The study concluded that the extent heads of schools perform the role of coaching to improve teachers’ professional development is too small. The study recommends that the government should finance both heads of schools and teachers’ trainings and seminars concerning their careers for their professional development.