The occurrence of three deaths and substantial morbidity among members of a "package tour" who stayed at the same hotel in Benidorm, Spain, during the summer of 1973 provided an opportunity to study the experiences of persons undertaking this type of holiday and some of the factors that might affect their health. Of 252 tourists, 164 (65%) reported illness, 86 of those affected (52%) having respiratory symptoms. The three persons who died had predisposing factors and all had lobar pneumonia. In the control group of 157 persons, who stayed at other hotels in Benidorm, 82 (53%) experienced ill-health during their stay but fewer (38%) had respiratory illnesses. The study demonstrated some of the hazards encountered by the inexperienced traveller and also indicated the need to improve surveillance of what appears to be an unexpectedly large amount of illness among international tourists.