Acute toxicity of copper and cadmium including median lathal concentration LC50 for tilapia species Oreochromis mossambicus). In static condition for a definite period of exposure was determined. The LC50 for 24 hours exposure to Cd and Cu and their mixture estimated graphically was found to be 1 mg, 2mg and 3mg/1, respectively. The LC50 of tolipia exposed for 72 hours exposure was found to be 2 mg/l. unlikely for Cu prolong exposure the LC50 values decreased proportionally with the exposure period. The uptake amount of metals was found to increase gradually with exposure concentration as well as period of exposure but accumulation did not follow the same pattern. The accumulated amounts were determined by atomic absorption spectroscopy.