Legionela can be primarily found in freshwater environments, natural or man – made water systems. Those artificially created are hot tubs, spa water, od air-condition. The critical points are blind ends in water plumbing systems where Legionella survive within biofilms, highly resistant biological structures. As known, Legionella parasite in amoeba and destroy it in favor of its own reproduction and survival. In this research we tested Legionella ability to survive in sea water samples.and tap water. Two strains of Legionella were used, a clinical isolate, L. pneumophila 130b and environmental isolate, L. pneumophila ST82 that was isolated from the sea water. The results showed that both strains of L. pneumophila do not grow after the first day in a chlorinated seawater sample. In the sample of non-chlorinated seawater, both bacteria survive an average of 20 days, while in non-chlorinated freshwater for more than 28 days. To conclude, both strains in the non-chlorinated seawater and freshwater survived for several days, indicating that it is necessary to constantly control and follow the protocol of the water maintenance in seawater pools, and in all water systems within the hotel. This would undoubtedly reduce the risk of legionnaires disease.