This study aimed at assessing the effectiveness of the heads of public schools in the delivery of secondary school curriculum implementation in Mbinga district. More specifically the study focused on the effectiveness of heads of school in the delivery of secondary school curriculum implementation in terms of improving managerial roles and skills and providing adequate resources. The study used a mixed approach whereby a non experimental design was adopted. The target population was 106 heads of schools and teachers of Mbinga district. Sample size for study was 12 heads of schools and 94 teachers from the selected public and private schools. Sampling technique for this study were probability and non probability whereby non probability was used to heads of schools and probability to teachers. Quantitative data was analyzed using the statistical package for social scientist (SPSS) 16.0 version program. Findings of the study indicate that availability of human and material resources, proper teacher management and improvement of school environment make successful implementation of secondary school curriculum. Also the consideration of needs of the society in teaching process and supportive living condition to teachers like good salaries and affordable houses to teachers make heads of schools to be involved in secondary school curriculum implementation. Moreover the unpredicted change of syllabus, lack of proper certified books and poor infrastructure in schools are the main challenges in the implementation of secondary school curriculum. The study recommends that the government and heads of schools of private schools must support and provide adequate resources in schools, good services to teachers like good salaries and train teachers in order to make them teach students effectively.