Total urinary catecholamines and plasma free fatty acids (FFA) were estimated serially in 50 patients with myocardial infarction (A) and in 27 cases of angina (B). A group of 24 normal healthy subjects (C) were also studied as controls. Catecholamines were significantly high (p is less than 0.001) in group A in the first 48 hours after infarction as compared to group C. Group B did not show significant variation from the normals (C). FFA also tended to increase only in group A in the first 48 hours. Both the parameters had returned to normal by 72 hours. The significance of the findings is discussed.