This paper examines the health effects of domestic water supply in the three residential density areas, in
Osogbo, Osun State, Nigeria. Having converted Osogbo representative map into digital format, it was divided
into 245 equal grids. One of every two grids was selected and 10% of the households in each selected grid were
systematically chosen for questionnaire administration. The study revealed that, smaller percentage (23.8%) of
respondents in the high residential density have access to public tap and private well in their houses. Also,
incidence of diarrhea (23.3%), stomach ache (20.2%) and typhoid(14.8%) is higher than the other two
residential densities. The chi square result obtained in each residential density (low = X2 = 27.259; p = 0.007;
medium = X2= 15.411; p = 0.115; high = X2 = 19.240; p = 0.008) indicated that there is a significant relationship
between water sources and ill health in the three residential densities in osogbo.