The first hantavirus infection outbreak in Poland (with different seroetiology) was identified between August-December 2007. Thirteen cases were reported in southeast Poland: 12 cases in the Carpathians bordering with northeast Slovakia, mainly in the forested areas of the Bieszczady mountains, and one case approximately 100-120 kilometres north from the others, in the adjacent Sub-Carpathian region. Four additional cases of past infection were identified retrospectively, based on the presence of the hantavirus specific IgG antibodies. Thus, the total number of infections identified in this area amounts to 17. Most probably, this number does not constitute the real hantavirus participation in the infections in this area. Considerable evidence for the probable participation of Dobrava virus (10 cases out of 17) and Puumala virus (3 cases out of 17) in the hantavirus diseases has been revealed. There were no fatal infections. However, out of 13 symptomatic cases, major HFRS clinical manifestations were observed in 10 cases and a typical nephropathia epidemica in the next 3 cases. Haemorrhagic diathesis was observed in 9 patients. Five patients underwent haemodialysis treatment due to acute renal failure. One, a female patient, haemodialysed in 10th week of gravidity, managed to maintain pregnancy and remains under interdisciplinary care.