To investigate the clinical characteristics, therapeutical approaches and outcome of infective endocarditis (IE). The clinical features, diagnosis, treatment and outcome of 70 IE patients who were treated in Peking Union Medical College Hospital from January 1988 to May 2000 were analyzed. Of the 70 consecutive cases who were diagnosed as IE according to the Duke's new criteria. 38 patients were male and 32 patients female. The average age was (36.1 +/- 16.6) years old. 8 cases were prosthetic valve endocarditis (PVE) and 62 cases native valve endocarditis (NVE). 57 of the 62 (91.9%) NVE patients had pre-existing cardiac abnormalities predisposing to IE, such as congenital cardiovascular disease (22 cases), idiopathic mitral valve prolapse (18 cases), rheumatic heart disease (12 cases), senile degenerative heart disease (3 cases), and permanent pacemaker (PM) implantation 2 cases. Fever (100%), anemia (57.1%) and embolism (47.1%) were the three most common clinical manifestations. Of the 42 cases who had a positive blood culture result, Streptococcus vividans (54.8%) was the most common isolated microorganism. 39 out of the 51 cases receiving antimicrobial therapy and 17 of the 19 cases being treated with combination of antibiotics and surgery were cured. 14 cases including 5 PVE and 2 IE after PM implantation died with a mortality rate of 20%. Intractable congestive heart failure was the leading cause of death. Congenital cardiovascular diseases and idiopathic mitral valve prolapse were the two most commonly found underlying heart diseases. Blood culture and echocardiogram should always be done to evaluate the possibility of IE while a patient presents with fever of unknown origin, especially when he or she has anemia or embolism. PVE, IE after PM implantation and intractable congestive heart failure were associated with a poor prognosis.