Staphylococcus aureus endocarditis cases in Denmark from 1976 to 1981 were reviewed. A total of 119 patients--61 female and 58 male, with a median age of 63 years (range, 1 month to 85 years)--fulfilled the diagnostic criteria. Community-acquired infections were most common (62%), but the frequency of hospital-acquired cases (38%) was greater than in earlier reports. The clinical picture was relatively nonspecific, and 32% of the patients had no heart murmurs initially. In 65 cases (55%), endocarditis was not suspected clinically, and the diagnosis was first obtained at autopsy. The mortality was 71% and correlated with age, hospital-acquired infection, and the presence of heart failure and arterial embolism.