In Europe, hantaviruses are zoonotic infections that can cause haemorrhagic fever with renal syndrome (HFRS). In Estonia the viruses have been found in Puumala and in Saaremaa. The well known symptoms of HFRS are fever, acute renal failure, abdominal pain, headache, blurred vision and thrombocytopenia. These findings should lead to clinical suspicion of hantavirus infection. Diagnosis is usually made on the basis of positive hantavirus IgM. However, hantaviruses can present a wide range of less known symptoms that can misguide clinicicians and lead to unnecessary diagnostic testing and overtreatment. Human infection occurs by inhalation of aerosolized virus-containing particles from rodent excretions. Hantavirus infects endothelial cells causing capillary leakage and other pathologic features leading to systemic signs of HFRS. This article presents a case of a 36-year old man who had high fever, diarrhoea, abdominal pain, headache and malaise. The clinical diagnosis of pneumonia was made based on laboratory and radiological findings. During hospitalization acute kidney lesion developed and HFRS was diagnosed.