Full text can be accessed at http://www.sciencedirect.com/science/article/pii/S0197397515002532The objective of this research was to evaluate effectiveness of private sector participation in solid waste collection and transportation in Dar es Salaam City. The study covered 20 private service providers in municipalities of Kinondoni, Temeke and Ilala. Information was collected through questionnaires, interview guides, physical observation and field studies. Data were sought from 5 private companies, 15 Community Based Organizations, Dar es Salaam City Council, Waste Departments of Municipal authorities and local governments of ward and streets. The results show that private sector service providers collected and transported 9% of the 29,764 tons of solid wastes generated per week. They have also provided employment opportunities to over 350 people, who are helping to keep the city clean and increase national income through payment of various taxes. It was also observed that private sector operates in difficult conditions because of low cost recovery, the use of inferior wastes collection and transportation equipment, limited scheduling, short contract duration, inefficient system of refuse fee collection, an absence of planned wastes recycling systems, inaccessible roads and weak implementation of relevant municipal policies and by-laws. It was further noted that the success of the system will depend on accountability of municipal authorities by raising the awareness of the communities in order to improve willingness to pay for refuse fees and discourage illegal dumping of waste by individuals, enforcing municipal by-laws, and planning and promotion of environmentally friendly waste management practices.