There are 26 districts and 86 union councils and it has 65 legislature seats. It (Balochistan) is a rich province with mineral resources and hot water in the shape of Gawadar Bay and deep sea port in Pakistan which needs developed workforce that can play an important role in having and using these resources accurately to make the province economically prosperous. The education sector is only one and most important sector, which can play its key role in the development of workforce through increasing the literacy rate of province. This research study tried to compare the performance of professionally developed and undeveloped teachers of public sector secondary school of Balochistan province of Pakistan where the high performing teachers satisfy the school administrator and student as well, but on other side poor performing teachers present the toughest challenge to school administrator. The poor performing teachers do not provide expected results even they distract others from doing their job properly. The unskilled behavior of these teachers de-motivates pupils and damages the school reputation. The aim of the study is to know about what makes a teacher to be a professional teacher and what makes a professional teacher to be an effective teacher who can show a sustainable professionalism in public sector secondary schools of Balochistan. The objective of this research is explained on page 6.It was significant to undertake a research to address the question of how professional development makes a teacher to be a productive and effective through his performance in real sense. The reasons for this research are highlighted in the contextual analysis, information about Pakistan, and government secondary education system in Balochistan. The mixed method of research was employed to achieve the research objectives. The data were analyzed through regression technique to explore the different dimensions of teachers' professional development as well as performance in government secondary schools of Balochistan. It is anticipated that on the basis of the results of this analysis, policy makers and educational managers can be suggested to enhance professional development opportunities to teachers to improve their performance and quality of education in the province It was my personal interest to conduct the research on the situation of secondary school teachers' professional development because I personally belong to Balochistan province and being a teacher, I wanted to know the reality about school teachers level of professional development and their performance.