The elderly in Tanzania face social insecurity that put them at risk of great horizon of abuse, social exclusion, serious illness and abject poverty. Although, there are several social institutions addressing the risks facing the elderly in Tanzania, still the elderly’s adverse conditions remain unabated. This paper examined Social Institutions (SIs) and their respective roles in providing social security to the elderly in terms of food, health, shelter, clothing and income services. The study adopted a cross-sectional research design where a questionnaire survey, focus group discussions and key informant interviews were the main methods of data collection. The descriptive statistical analysis was employed to explore the distribution of socioeconomic characteristics and social protection. Content analyses approach was used to analyses the qualitative data. The findings show that: the family, Department of Social Welfare (DSW), Tanzania Social Action Fund (TASAF) and religious institutions were the most active SIs providing social protection to the elderly. Elderly were unsatisfied with the SIs’social services provision as they narrowly focused on health and food. There was inadequately provision of other needy services. The study recommends to government to enhance the implementation of the social protection policies and guide service provision mechanisms among SIs. There Sis should adopt joint implementation of the social protection interventions to improve the scope of services for elderly welfares.