This study explores the power of self-help associations by examining the contributions of Community-Based Organizations (CBOs) in environmental sanitation with particular reference to Metropolitan Kano- the most densely populated state in Nigeria. The study adopted explorative method of research using both quantitative and qualitative methodologies. A total of two hundred and two respondents were sampled. There were sixty-eight executive and active members of CBOs who participated in eight Focus Group Discussion (FGD) sessions; up to 120 questionnaires were administered on residents of the six Local Government Areas of the metropolis; and as many as fourteen stakeholders were engaged in in-depth Interviews. CBOs are self-help associations established with the major objective of social and economic development of the communities they live in and beyond. Findings of this research revealed that CBOs perform various environmental sanitation activities including: construction and maintenance of bridges, culverts and drainages, clearing of grave yards, spray against malaria, pests and insects,mobilization campaigns and public enlightenment on the importance of sanitizing the environment.