The present study was carried out by the Aeronautic Medicine Section of Alitalia at Fiumicino, where in the years 1976-1977 and in the first four months of 1978, 6700 samples of serum from ground and air personnel were analysed as part of a preventive medicine check-up. A high percentage of positivity (9 per thousand in 1976, 12 per thousand in 1977 and 11 per thousand in the first four months of 1978) was observed. The problems of continual travelling and staying in countries were syphilis presents a very high morbility rate are the reasons for the infection. Social, sanitary, deontological and human problems of department physicians delegated to treat the disease are discussed.