The study determined the effectiveness and responsiveness of decentralization policy in the first district of Ilocos Sur. It employed the descriptive survey research design with documentary analysis on the provisions of Republic Act No. 7160 in the areas of basic services. The findings revealed that the group respondents had favorable responses with a descriptive evaluation of highly effective in areas on Community-Based Forestry Projects; Municipal Agricultural Services; Health Services and Social Welfare Services. Furthermore, the group respondents have similar view as to the effectiveness and responsiveness on the decentralization policy for extension and on-site services and facilities and infrastructure services. It is indicated in this study that the visibility of the projects provides better insights in evaluating the development programs of the LGU. However, there are varied responses as to the effectiveness and responsiveness of decentralization policy for health services and social services. The primary respondents provided an objective evaluation as to how they implemented their programs while secondary respondents evaluated the current state of health services and the social services in the LGU.