A descriptive term nonbacterial thrombotic endocarditis (NBTE) is used currently instead of the former name marantic endocarditis. The study describes 171 cases of NBTE encountered in autopsies over a period of 22 years (an incidence of 0.93% in adults). Malignancy was present in 59% of cases. Tumors relatively most frequently associated with NBTE were carcinomas of the ovaries, biliary system, pancreas, lung, and stomach. The vegetations were located mostly on the left-sided valves (mitral 64%, aortic 24%, both 9%). The involved valves were otherwise normal in 82%, and they were previously damaged in 18%. Systemic emboli from valvular vegetations occurred in 41% of patients, with splenic, cerebral, and renal circulations being most frequently affected. Pulmonary embolism was noted in 43%. The state of nutrition at autopsy was within normal limits in 35%; there was undernourishment or cachexia in 40%, and overweight or obesity in 22% of patients. The main pathogenetic factor in NBTE seems to be a state of hypercoagulation.