Acute toxicity bioassay of three different heavy metals copper (Cu), lead (Pb) and cadmium (Cd) for the freshwater catfish, Clarias batrachus were conducted for evaluation of the toxicity. The 96h LC 50 values recorded for Cu, Pb and Cd were 15 ppm, 29 ppm and 35 ppm respectively. The results of this study indicate that the order of toxicity of these heavy metals is Cu>Pb>Cd in short duration acute toxicity experiments. The toxicity was found to be dependent on dose and duration of experiment for all these heavy metals. Cu was found to be much more toxic than Pb and Cd to C. batrachus.