This study refers to the clinical features of 11 cases of hemorrhagic fever with renal syndrome (HFRS) which was prevalent in Nagoya City University Medical School. The clinical course was divided into two parts: the febrile stage and the polyuria stage. Symptoms such as lumbago, muscular pain, general malaise and anorexia disappeared along with a fall of fever. The incubation period of this disease was estimated to be about three weeks. Polyuria, proteinuria, gastric complication and impairment of liver function seemed to be some of clinical features of this disease. There was no HFRS patient with severe renal failure in our cases. The presence of disseminated intravascular coagulation (DIC) was confirmed in 3 of these 11 cases. Therefore, it was suggested that hemorrhagic tendency of this disease might be attributed to DIC. From our experiences, the most important factor for the treatment of the severe case was the earliest detection whether they were complicated by DIC or not. If they were suspected of DIC, it could be necessary to start treatment for DIC as soon as possible. Prophylactic measures for HFRS in our animal facility could contribute to the prevention of this disease.