The aim of this study was to analyse the influence of patient characteristics on delay between onset of symptoms and hospital admission (patient delay) in acute myocardial infarction, and especially to assess the impact of risk factors for acute myocardial infarction on patient delay. A group of 6676 consecutive patients with enzyme-confirmed acute myocardial infarction, admitted alive to 27 Danish hospitals over a 26 month period from 1990 to 1992, were studied. Due to missing information on delay or in-hospital acute myocardial infarction 698 patients were excluded, leaving 5978 patients for analysis. Mean patient delay was 9.1 h, median delay 3.25 h (5 to 95 percentiles: 0.67-40.0 h). Thirty-four percent were admitted within the first 2 h, 68% within 6 h and 81% within 12 h of onset of symptoms. In multivariate logistic regression analysis, a greater than 2 h patient delay was independently associated with male gender (odds ratio (OR) = 0.809, P = 0.003), increased age (P = 0.0001), diabetes mellitus (OR = 1.269, P = 0.03), left ventricular systolic function (wall motion index) (P = 0.02), onset from midnight to 0600h (OR = 1.434, P = 0.0001), onset on a weekday (OR = 0.862, P = 0.04), history of angina pectoris (OR = 1.198, P = 0.02), chest pain as initial symptom (OR = 1.293, P = 0.02), ventricular fibrillation (OR = 0.562, P = 0.0001), ventricular tachycardia (OR = 0.620, P = 0.0001), Killip class > or = 3 (OR = 0.709 P = 0.002), presence of ST elevation (OR = 0.810, P = 0.01) and ST depressions (OR = 0.847, P = 0.01). All these variables, except history of diabetes mellitus, angina pectoris, and chest pain as an initial symptom were also associated with a delay of more than 6 h. Thrombolytic therapy was administered to 55.8% of patients admitted within 2 h of an acute myocardial infarction, 48.5% of patients admitted within 2-6 h, 31.5% of patients admitted after 6-12 h and 11.9% of patients arriving later than 12 h after start of symptoms. CONCLUSION. Patient delay continues to be disappointingly long. This also applies for patients at a high risk of acute myocardial infarction (notably those with a history of diabetes mellitus and angina pectoris).