Hantavirus infections, Puumala serotype, is a well-known disease in the northeast of France, but not in the Paris area, despite regularly diagnosed cases. A retrospective study was performed from January 1999 to December 2000 to assess the clinical and epidemiological characteristics of this disease in the "Région Ile-de-France". Fourteen cases were diagnosed. All required hospitalisation. Patients presented usually with high fever, pain, renal failure, moderate thrombocytopenia and, sometimes, transitional acute myopia witch is pathognomonic of the disease. In each case, a contact with a forest was found. Twelve patients recovered completely. One patient with pre-existing chronic renal and hepatic failure died and another developed a persistent arterial hypertension. Invasive procedures were often used before the diagnosis. Hantavirus infections does exist in the "Région Ile-de-France". Failure to recognise this disease in this area lead to unnecessary invasive procedures and hospitalizations.