Dimethyl 2, 2-dichlorovinyl phosphate is an organophosphorus insecticide used in the control of several plant and animal pests. This study evaluated the effects of dimethyl 2, 2-dichlorovinyl phosphate on the electrolytes (calcium, sodium and potassium) in the kidney and liver of Clarias gariepinus. The fish samples were purchased from private farm in Aluu Port Harcourt, Nigeria. The fishes were carefully housed to prevent contamination and three different concentrations of the toxicant were prepared i.e. 0.00ppm, 0.10ppm and 0.20ppm. At the end of the experiment (four days), the fishes were dissected and the internal organs i.e. liver and kidney were collected and 0.5g of each macerated, and a few drop of physiological saline added before centrifuging at 3000 rpm for 10 minutes. The calcium, sodium and potassium content were analyzed using standard methods. Results showed that calcium, potassium and sodium ranged from 0.80 – 1.40mg/l, 3.80 – 7.10mg/l and 10.20 – 16.40mg/l respectively (Kidney) and 1.00 – 1.13mg/l, 10.60 – 17.73mg/l and 6.80 – 12.80 mg/l respectively (liver). With the exception of calcium there was significant variations (P<0.05) among the various concentrations of sodium and potassium. The study confirms that dimethyl 2, 2-dichlorovinyl phosphate can alter the electrolytes balance of Clarias gariepinus
