The analysis of heavy metals in drinking water from different sources in Lagos state, Nigeria were determined with a view of comparing the effects of level of Industrialization, population density and urbanization on the water quality in the centre of Lagos and off town of Lagos (Ikorodu LGA, a relatively less Industrialized and less Urbanized town of Lagos state) as a case study. The different sources of drinking water considered were wells, boreholes, surface water and tap water. In each of Lagos and Ikorodu. The heavy metals were analysed; Pb, Cd, Cu, Fe, Cr, Zn, Na, Ni, Mg and Ca using Atomic Absorption Spectrophotometer (Perkin-Elmer 305B model with air-acetylene flame). The results show that Pb, Ni, and Mg values exceeded the permissible limits set by WHO, EU and NIS for all the samples from all the sources in all study area while Fe has values above the standards set by all the regulatory bodies in Ikorodu boreholes (i.e. 1.804 mg/L) but all other sources as well as all Lagos samples have values of Fe within the permissible limits (0.2-0.3 mg/L) and this could be traced to the geology of the area. Cu, Zn, Na, Cr, and Ca all have higher values in Lagos centre samples than in Ikorodu samples but are all within the permissible limits. Cd was not detected in any of the samples at all.