A total of 42 Japanese centenarians (9 males & 33 females) autopsied in Tokyo Metropolitan Geriatric Hospital during 22 years (1975-1996) were clinico-pathologically examined to determine details of the main cause of death. The main cause of death of the 42 cases were sepsis (16 cases), pneumonia (14 cases), suffocation (4 cases), heart failure (4 cases), cerebrovascular disorder (2 cases) and malnutrition (2 cases). Most pneumonias were caused aspiration of foreign bodies, and the origins of sepsis were pyelonephritis (7 cases), biliary tract infection (3 cases), necrotic lesions of the intestine due to ileus, ischemia and pseudomembranous colitis (3 cases) and indwelling vein catheter (3 cases). Malignant neoplasms were observed in 16 cases (38%), and 5 of them had 2 or 3 lesions. Thus, the total number of lesions of malignant neoplasms were 22, as follows; colonic cancer (36%), urinary bladder cancer (14%), lung adenocarcinoma (9%), gastric cancer (9%), malignant lymphoma (9%) and others. However, none of these malignant neoplasms were directly related with the cause of death. All 42 centenarians died not of simple "senile decay", but due to diseases.