A case of splenic tuberculosis is reported. The patient was a 79-year-old man who was admitted to the Tokyo Metropolitan Geriatric Hospital because of high fever and loss of body weight. Several finger-tip sized superficial lymph nodes were palpable in bilateral inguinal regions. The intermediate PPD skin test was positive. However, there was no evidences of active tuberculosis on the chest roentgenogram. The computed tomogram of the abdomen showed moderate enlargement of the spleen with multiple low density areas and several swollen lymph nodes in the para-aortic region. Although a lymph node of the inguinal region was resected for the pathologic examination, it showed no specific changes. In order to obtain a final diagnosis, laparotomy was performed. The spleen was markedly enlarged and nodular in appearance. No abnormal findings were observed in the other abdominal organs. Splenectomy was carried out. Numerous yellowish nodules, varying from 0.1 to 5 cm in diameter, were observed on the cut surface of the resected spleen (20 x 20 x 8 cm, 700 g). The bacteriologic examination revealed acid-fast bacilli. The fever subsided after splenectomy and following antituberculous therapy. Recently, isolated tuberculosis of the spleen has become very rare. Since 1965, only six cases in five reports can be found in the English, French and German literature. The present case is considered to be one such very rare cases of tuberculosis. Although splenic tuberculosis is rare at the present time, splenic tuberculosis should be included in the differential diagnosis of fever of unknown origin with splenomegaly.