42 patients with the clinical evidences of endocarditis were examined by echocardiography. In 28 of 42 cases(66.7%) vegetation was present, whereas in 14(33.3%) vegetation was not visualized. Alpha-hemolytic streptococcus was the most common infecting organism(47.6%) and rheumatic heart disease was the most common predisposing heart disease(47.6%). Patients with echocardiographically demonstrable vegetation had a higher incidence of congestive heart failure compared to the patients without vegetation(75.0% vs. 21.4% p<0.05). But major embolism was not significantly different in the two groups. Mortality was higher in the patients with vegetation than in the patients without it(39.3% vs. 0%, p<0.05). Among vegetation positive patients, mortality was highest in aortic valve patients.(58.3%) So patietns with aortic valve vegetation should be regarded as high risk group and early surgical intervention should be considered if indicated. The causes of mortality were congestive heart failure(45.5%), cerebral embolism(36.4%), myocardial infarction(9.1%) and ventricular tachycardia(9.1%) in decreasing frequency.