The study focused on assessing the commitment of central agencies on the implementation of decentralization by devolution at all levels of the government. Specifically the study aimed to; identify the extent to which central government devolve full power and responsibility to local government for service delivery; to determine and explain the level of participation on decision making process and to identify the effect of decentralization by devolution at local level in the improvement of service delivery; and to identify which plans are given priority, between those of central government and local government in case of shortage of funds which may lead to cut down some of activities. A case study research design was applied, employing both primary and secondary data collection methods in order to find out answer to research objectives. Data collection was done using interview, questionnaire and documentary review. The study covered 47 respondents. The data were analysed by using various statistical techniques such as SPSS, for qualitative data which were then presented using percentages and frequency distribution. The qualitative data were also analysed using content analysis where the researcher edited, coded and arranged the pattern of information into themes. With regards to the extent to which central government devolves power and responsibilities for service delivery at the Moshi District Council, the findings revealed that some of responsibilities and power are not decentralized to enable easy service delivery. There many areas which are not decentralized but most of the respondents mentioned land and settlement, permanent employment (recruitment of civil servant) formulation of policies, promotion issues, heavy tax and implementation of heavy donor funded projects. This implies that, though the central government has devolved some of the power and responsibilities to local governments, still there are some important areas of service delivery which are coordinated by the central government. In addressing the second objective, the study found that there is ineffective participation in decision making at grass root level. The responses revealed that there is moderate participation in decision making, which implies that people at grass root level are involved to some extent in decision making and in strategic planning. Sometimes, lower level governments are involved in making the budget, but they don’t have the power and authority to make a decision on other things such as land and settlement and formulation of the policies. Concerning the effect of decentralization at local level in the improvement of service delivery, the findings of the study revealed that decentralization by devolution has brought both negative and positive impacts. The negative impacts of decentralization include the increase of bureaucracy and the way it has opened a room for politicians to interfere professionals when they perform their activities. The positive impacts of decentralization include the improvement of service delivery, as well as improvement of good governance. D by D is an obligatory tool for poverty reduction because it gives room for the citizens to participate in strategic planning for the development of the council. The findings also revealed that the plans of the central government are given priority than those of local government. The findings show that some plans of local government are not given priority and are not attained as they are scheduled by the local governments because the funds to implement those projects are planned from the central government. Based on the findings, the following measures are recommended to enable the commitment on the implementation of the decentralization by devolution at local level; the central government needs to ensure complete and accurate decentralization of power and authority to lower levels of the government as well as training people on how to implement D by D, the leaders at lower levels should be given seminars or training to build their ability to make proper arrangement of meetings, Central government should encourage the local government on improving their own source of income and should not interfere the implementation of those funds for the project development Also local government should be given the power and authority to collect taxes from the big investment and enough resource (funds) should be allocated to the decentralized activities for its implementation