Microbial content of wastewater in two abattoirs and the impact on microbial population of receiving soil was studied in Agege and Ojo Local Government Areas in Lagos State, Nigeria. Wastewater samples were collected from each of the abattoirs over three months period and examined for microbial content. Soil samples contaminated with the wastewaters were also collected and analyzed for microbial content as compared to soil without wastewater contamination in the neighborhood (control). Some physico-chemical parameters of the samples such as total dissolved solid, chemical oxygen demand, etc., were examined. The wastewater samples from both abattoirs were highly contaminated; Agege abattoir showed mean bacterial count of 3.32 × 107 cfu/ml and Odo abattoir showed mean count of 2.7 × 107 cfu/ml. The mean fungal populations were 1.6 × 105 and 1.2 × 105 cfu/ml for Agege and Odo abattoirs respectively. In the contaminated soil sample, mean bacterial count was 3.36 × 107 cfu/ml compared to the 1.74 × 106 cfu/ml of the control sample. High microbial load in abattoir wastewater with negative effects on microbial population in soil, in this study, further confirmed the need to treat wastewater rather than discharging it to the environment
