Religious institutions may be agents of advocacy, funding, innovations, empowerment, social movements and service delivery. This paper attempts to investigate the impact of religious and educational institutions in the livelihoods of the pastoral Maasai. The study was conducted in Monduli District. A cross-sectional design was adopted whereby structured questionnaire was administered to collect primary data. Secondary data were collected from District, religious and educational institutions' offices. A sample of 140 respondents was drawn from the population. The Statistical Package for Social Sciences software was employed for data analysis. From the findings it was observed that religious and educational institutions play their roles in changing the livelihood of the pastoralists by establishing and supervising various socio-economic activities aiming at poverty reduction. These projects include formal education and health services, water supply, food security and income generating activities. Participatory approach is adopted for the sustainable development projects. The opinions of beneficiaries were sought and it was found that religious and educational institutions had brought positive changes on the livelihoods strategies and systems of the pastoralists. It is recommended that religious and educational institutions and other development activists should introduce similar interventions for other tribal people particularly the Barbaig, Hadzabe and Sandawe. Their livelihood patterns need to be changed because of the changing environment.