In this study, the level of toxic metals and organochlorine pesticides (OCPs) in the simulated leachate of the soil of a cocoa farm and a nearby river was investigated. Potential mutagenic and genotoxic effects of the river and simulated leachate were evaluated using Ames Salmonella fluctuation assay (Salmonella typhimurium strains TA100 and TA98) and SOS chromotest (Escherichia coli PQ37), respectively. The level of copper, cadmium, arsenic, chromium, nickel, lead, and iron in both the simulated leachate and the river sample was higher than the allowable maximum standard. The concentration of total OCPs was 9.62 and 108.89 mu g/L in the river sample and simulated leachate, respectively. The concentrations of total hexachlorocyclohexanes and dichlorodiphenyltrichloroethane were significantly higher than the standards. Dichlorodiphenyltrichloroethane was the main pollutant in the two samples. Data from the Ames Salmonella fluctuation assay indicated that the tested samples were mutagenic. Similarly, the data from the SOS chromotest corroborate the Ames assay's result. In the E. coli PQ37 system, the two samples induced significant SOS response, an indication of genotoxicity. Comparing the two microbial assays, the E. coli PQ37 showed a slightly higher sensitivity than the Ames Salmonella assay for the detection of genotoxins in the present study. The chemical and organic constituents of the samples were believed to induce these reported genetic and mutagenic effects. These results showed the environmental pollution caused by the indiscriminate use of pesticides in cocoa farming and the potential effects the pollutants might have on exposed aquatic organisms and the human populace.