Dissertation (MA Education)The overall quality of teacher education in Tanzania has increased. However, Chemistry teachers are still faced with some problems in teaching specific topics. These problems have been hardly addressed through the in-service programmes attended by the teachers. Consequently, Chemistry teachers lose confidence in addressing the problems they encounter in their classrooms. The study, therefore explores the topics in Form I;s perceived difficulties in teaching and learning of Chemistry during a school based professional development (PD) programme. This was an attempt to support teachers’ competencies in implementing effective lessons in Chemistry classrooms in secondary schools in Tanzania. The study was conducted in Shinyanga Region in Tanzania. A total of one hundred and fifty (150) Form II students were interviewed to identify the topics perceived difficult to study when they were in Form I classes. Also, a total of fifteen (15) teachers teaching Chemistry in Form I were involved to identify the difficult topics using questionnaires and later provide detailed description on the identified topics. Furthermore, two (2) expert teachers and one (1) School Quality Assurer participated in reviewing and appraising the established school based PD programme established. The action research orients itself where an exploratory sequential was sandwiched in the quasi-experimental design. The design was used to guide the exploration of difficult topics in teaching Chemistry subject, prototyping, and assessing the established school based professional development programme. The findings indicated that Laboratory techniques and Safety, the scientific procedures, and Matter were the most difficult topics identified by both teachers and students in Form I Chemistry subject. The most important features of the developed programme were identified to be: at the resource centres, peer-teacher visiting in schools and observing lesson implementation in the classrooms and post lesson discussions where teachers share strengths of the lesson and area for improvement for students’ maximum learning. The study concludes that any professional development programme initiated by teachers themselves is likely to bring about effectiveness in terms of teachers’ growth and students’ learning. The study therefore recommends that, the culture of bottom-up supporting of teachers in development of lesson materials should be promoted at all levels of education system including the Tanzania Institute of Education (TIE) and other curriculum developers.