This study evaluates the occurrence of various risk indicators, with particular emphasis on serum lipids one year after a coronary event (development of acute mycoardial infarction (AMI); exposure to either coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA), prior to and after presentation of the main results from the 4S study. Patients under 70 years of age either hospitalized for AMI or undergoing CABG or PTCA at Sahlgrenska University Hospital in Göteborg were evaluated one year after the event. Patients who had an event during the period January 1, 1993 until December 31, 1993 were evaluated one year later (Period I) and those who had an event during the period September 1, 1995 until August 31, 1996 were evaluated one year thereafter (Period II). In total, 293 patients were evaluated during Period I and 284 during Period II. Mean total serum cholesterol levels fell from 6.2 mmol/l during Period I to 5.3 mmol/l during Period II (p < 0.001). The proportion of patients with serum cholesterol < or =5.0 mmol/l increased from 15% during Period I to 40% during Period II (p < 0.001). The mean low-density lipoprotein (LDL) levels fell from 4.0 mmol/l during Period I to 3.2 mmol/l during Period II (p < 0.001). The proportion of patients with LDL < or =3.5 mmol/l increased from 32% during Period I to 68% during Period II (p < 0.001). The proportion of patients using lipid-lowering drugs increased from 25% during Period I to 57% during Period II (p < 0.001). Among patients with coronary artery disease who had either developed AMI or undergone CABG or PTCA, a marked increase in the use of lipid-lowering drugs has been observed in a university hospital in Sweden after presentation of the results of the 4S study. Parallel to the increased use of lipid-lowering drugs, we observed a substantial lowering of serum lipids.