The hosts of Hantavirus are rodents, while they are transmitted to humans via aerosol, or by direct contact with them. The primary goal of the study was evaluation of the state of health of forestry workers by laboratory diagnosis of the diseases caused by Hantavirus Dobrava/Hantaan. The study covered a group of 820 randomly selected employees of the State Forests from 32 Forest Districts located in the area of the whole of Poland. The results of the study show that the largest number of positive results were registered in the Augustów Forest District – 3 cases (10%), and in Piotrków Trybunalski – 3 cases (11.5%). For the whole of Poland, 25 seropositive results were noted (3%) and 76 results were doubtful (9.3%). The results of the conducted study suggest the occurrence of Hantavirus Dobrava in large forest complexes on the territory of Poland. People residing and working in these areas are exposed to infection, and this exposure seems to be comparable with data from other countries.