The normal range of lactate is 0-2mmol/L and value above it is considered as hyperlactatemia. It may arise due to adequate and non-adequate oxygen supply mechanisms. The major reason is likely stress –induced aerobic mechanism which shows raised results of lactate. Increased lactate levels can cause acidifying effects on the blood. There are many etiological reasons for lactic acidosis like disease condition, deficiency and alcohol. Early and late onset are two categorization for patient with hyperlactatemia after cardiac surgery. OnE being the major trigger factor for lactic acidosis in cardiopulmonary surgery patients due to tissue hypoperfusion. So preventive measures before cardiac surgery should be taken.