Static bioassay tests were carried out in order to evaluate LC50 values of Cadmium Chloride for freshwater stinging cat fish, Heteropneustes fossilis as well as to observe behavioural alterations posed by Cadmium. The LC50 values for 24h, 48h, 72h and 96h were found 434.74, 409.88, 401.31 and 392.92 mg/l, respectively. The major behavioural alterations observed during the experiments were erratic swimming, restlessness, muscle spasm, profuse mucous secretion, discolouration of the integument and cutaneous ulcerations in exposed animals. Overall increase in opercular beats in exposed fishes was also recorded throughout the experiments.