Background: Analyses show that the concentration of air-ions in ship cabins almost always remains at levels lower than the required norms. Therefore, in this study possibilities of complementing the deficit of these particles were examined. Materials and Methods: The research was carried out in a laboratory using ionisers and metal pipes with proper parameters, and then in the ventilation ducts of ships. Results: The study showed that we can achieve the needed levels of air-ions in ship cabins by installing single ionisers with the capacity of delivering about 1 mln ions/cm3 in proper sections of the ventilation ducts. Med Pr 2010;61(3):299-306