The infection with Mycobacterium marinum is a rarely diagnosed disease. This bacterium occurs in bodies of fresh or salt water in various parts of the world. When a German swimming pool technician became ill, the possibility that the illness was caused by an occupational exposure was investigated. In the present article, the clinical features of this case are described. The infection was caused by exposure of inadequately protected skin with minor wounds to untreated salt water. It took more than a half year until the medical therapy was successful. Then the nodular alterations on the skin of hands and forearms healed leaving scars. It was recommended that the social insurance accept the case as an occupational disease or an occupational accident (minor wound with subsequent infection). Occupational skin protection for technicians working at the salt water swimming pool had to be improved. The case demonstrated the necessity for documentation of minor injuries such as cuts and scrapes caused during working time. Bathing people are not endangered, provided the chlorination of the swimming pool water is effective. However, people with skin wounds may be at risk when handling fish or cleaning an aquarium or bathing in the sea.
