The 4S study was followed by guidelines for statin treatment of patients with manifest coronary heart disease recommending statins for patients with serum cholesterol above 5.5 mmol/l, age below 70 years, and more than three years life expectancy. The purpose of the present study was to investigate how these guidelines were implemented in clinical practice. A retrospective registration was conducted on two cohorts of patients; patients with myocardial infarction in 1994 (before 4S) (n = 101) and 1996 (n = 100). Risk factors for coronary diseases and the use of statins were registered from the patients records. No significant differences in risk factors between the two cohorts were observed. The proportion of patients given statins increased from 4% in 1994 to 40% in 1996, whereas 50% of patients with serum cholesterol above 5.5 mmol/l were given statins in 1996. Statin treatment was usually instituted during hospitalization. Awareness of actual prescription and handling of statin treatment, and adaption of knowledge from clinical studies to clinical practice is probably needed for further improvement of statin treatment.