The in-hospital prognosis of patients with definite acute myocardial infarction (AMI) treated at the University Medical Center in Marburg, Germany, was retrospectively evaluated for the years 1977 to 1978 and 1988 to 1989. Diagnosis of AMI was established in 357 patients (251 men, 106 women) in 1977 to 1978 and in 338 patients (240 men, 98 women) in 1988 to 1989. Overall in-hospital death rate increased from 19.6% (1977 to 1978) to 28.7% (1988 to 1989) (p < 0.01). Median ages of both groups were comparable. Patients treated in 1988 to 1989 had a higher prevalence of arterial hypertension (p < 0.001), hypercholesterolemia (p < 0.0001), reinfarction (p < 0.01), and successful resuscitation before hospital arrival (p < 0.0002). Univariate risk factor evaluation suggested the following unfavorable prognostic variables: age, successful resuscitation before hospital arrival, diabetes mellitus, reinfarction, and female sex. A favorable prognosis was associated with a history of smoking, higher serum cholesterol concentration and thrombolysis. Logistic regression analysis identified age, smoking, serum cholesterol concentration, and the combination of treatment period with either successful resuscitation before hospital arrival, or diabetes mellitus, as independent variables of in-hospital prognosis. In conclusion, the apparent increase of in-hospital death rate between 1977 to 1978 and 1988 to 1989 could mainly be attributed to differences in the 2 study groups.