The toxic stress of a commonly used dispersant (Caamol lubri-clean) on freshwater shrimp, Desmoscaris trispinosa, and brackish water shrimp, Palaemonetes africanus, was tested. The mean percentage mortality obtained for the 10-day experiment duration was 20, 60, 80, 100, 100% (freshwater test) and 20, 40, 63, 83, 100% (brackish water test). The 10 d median lethal concentration (LC₅₀) was estimated using the Finney Probit method of analysis and was found to be 53.33±3.52 mg/kg and 78.24±6.11 mg/kg for the fresh and brackish water acute toxicity tests, respectively. The release of dispersants into aquatic systems may affect bottom dwelling organisms inhabiting such environments due to the toxic nature of the surfactant component in the dispersant.