The paper assessed the effects of wastewater on socio-economic activities of residents in Kano metropolis, Kano State, Nigeria. High population, poor drainage channels and lack of central wastewater sewerage and functional treatment plants have necessitated indiscriminate discharge of wastewater into the environment. Using Krejcie and Morgan (1970) table for determining sample size, a total of 384 population size was sampled and purposefully, systematically and randomly administered questionnaires in Likert Scale Format. Interviews were also conducted with stakeholders and community elders and direct filed observation for elucidation of the socioeconomic effects of wastewater. Results were presented in tables and charts and further expressed in strength of associations using Spearman rho statistics analysis. Findings show that 89.75% of respondents are of the view that wastewater from households and commercial areas is let loose into the environment and affects land-use as well as domestic activities. It also shows that 88.5% reported that wastewater affects the means of livelihood of residents and 92.19% opined that economic cost of construction of drainage channels, embankment and sandbags while 92.5% strongly and agreed that wastewater affects the health of the residents and causes different kinds of diseases. The study further shows that wastewater has effect on businesses and recreations while making some places inaccesible and affectng their economic activities. The study therefore recommends public enlightenment, strong legislations and enforcement of principle of polluter pays, attitudinal change and population decongestion, centralized sewerages system should be implemented among others should strictly be adhered to harness to encourage socio-economic activities.