Two groups of patients underwent cardiopulmonary bypass for different types of cardiac lesions. The bypass time, the aortic cross clamp period and all other procedures were similar in both groups. In one group single large dose of corticosteroid was given prior to the induction of anaesthesia in anticipation that it will affect the stability of cell membrane and reduces the deleterious effects of cardiopulmonary bypass. The results of the study showed most of the parameters to the similar in both groups except the alkaline phosphatase which was not affected when corticsteroids were given. Serum bilirubin was not raised in patients recieved dexamethazone and blood replacement was less in the post operative period in the same group