A Dissertation Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Public Administration (MPA) of Mzumbe University Dar es Salaam Campus CollegeThis study seeks to examine the extent to which Non-government organizations are performing a complementary role to the government in promoting good governance. The major aim was to understand the role of Non-government organizations in improving good governance in public sector. The research used both quantitative and qualitative data obtained from primary and secondary sources. The findings revealed that Non-government organizations are playing the significant role in improving good governance in public sector. Many Non-government organizations emphasize the adoption of the principles of good governance such as accountability, transparency, value for money, ethics, participation and rule of law in running public sectors. The principles of good governance must be adopted in public governance so that the government may meet the public interest. The findings also revealed that the Non-government organizations uses media, seminars and trainings, citizens’ engagement programs, information access, policy analysis and advocacy to emphasize rule of law, ethics, participation, accountability, transparency and value for money in the public sector. Apart from the above fact, the findings revealed that Non-government organizations face different problems in carrying out their activities such as lack of financial resources, lack of government cooperation, government interferences, citizens’ awareness and lack of qualified personnel. Through commitment to greater openness, transparency, participation, ethics, rule of law and accountability from all parts in the public sector it was felt that the common goal of bringing good governance in the public sector in Tanzania is possible.