To better define the overall characteristics and risk factors for dying of adult pneumococcal endocarditis (PE) focusing on the echocardiographic diagnosis, the impact of surgery, and emergence of penicillin resistance, the medical and microbiologic charts of adult PE cases observed between 1991 and 1998 in university and general hospitals were reviewed through a nationwide retrospective study in France. Thirty cases of PE (22 men, 8 women; median age, 53 yr; range, 27-87 yr) were collected and validated. Twenty patients (66.7%) had no known predisposing cardiopathy; 4 had a bioprosthetic valve. The primary focus of infection was pneumonia in 10 (33.3%), and meningitis was noted in 12 (40.0%). Half the patients suffered from chronic alcoholism. Echocardiography detected vegetation(s) in 29 cases (96.7%), valvular perforation in 6 (20.0%), and/or valve ring abscess in 4 (13.3%). The most frequent complications were congestive heart failure (n = 19), large arterial emboli (n = 8), and focal abscesses (n = 7). Five strains were penicillin-resistant. Twenty (66.7%) patients underwent valve replacement, 12 of them during the first month. The overall mortality rate was 24.1%. According to a multivariate analysis, the risk factors independently associated with dying were age > or = 65 yr and septic shock, while cardiac surgery was protective (p < 0.01). In conclusion, PE is usually fulminant and causes severe valve damage and embolic complications; its short-term prognosis might be improved by early valve replacement.