Travel for business or tourism has become increasingly common in the age we live in. The great volume of national and international traffic and the speed of transportation are inevitably linked to a possible increased risk of acquiring certain illnesses such as Legionellosis, which, in fact, has shown a consistently increased incidence in recent years. In this paper, a brief introduction regarding the etiology and clinical and epidemiological characteristics of the disease, is followed by recent national and international data regarding its diffusion and guidelines for its prevention and control.