The relation of a serum cholesterol level obtained during acute myocardial infarction (AMI) to the patient's usual baseline level is unclear. Many physicians tend to ignore cholesterol levels measured during AMI and will wait several months before obtaining a repeat cholesterol measurement; in many instances this delays interventional programs. Using the Framingham study cohort of patients, the records of all persons sustaining AMI were reviewed. Eighty-three patients were identified who had total cholesterol (TC) levels recorded within 2 years of AMI, within 24 hours of hospitalization for AMI and within 2 years after hospital discharge. In these persons, there was no statistically significant difference in the TC values measured at these 3 times. Thus, TC levels drawn within the first 24 hours of AMI accurately reflect a baseline level and can be used in instituting intervention programs.