Kibale National Park (KNP), Uganda, has a number of chimpanzees habituated for tourism. The close genetic relationship between humans and chimpanzees means that there is the potential for disease transmission between the two. The aim of this study was to establish the diseases to which chimpanzees may be exposed by surveying the medical histories of humans in contact with the chimpanzees of KNP. Medical questionnaires were given to tourists visiting KNP and to the population of a village close to the park. The 62 tourist surveys returned indicated a high prevalence of disease symptoms, in particular diarrhoea, as well as ongoing infectious diseases and a lack of current vaccinations. The 50 local surveys returned also indicated a high prevalence of disease symptoms, in particular respiratory disease, along with a low rate of vaccination and a high frequency of visual contact with the chimpanzees both within and outside KNP. This study indicates that humans are a potential source of infection for chimpanzees. The results, which have been communicated to the appropriate authorities, will assist in the devising of proper tourist viewing regulations and provide local health authorities with the information necessary to improve both public health and chimpanzee health. Further recommendations include education of tourists regarding appropriate vaccinations, hand washing prior to the visit, the use of facemasks during the visit, and the provision of latrines. Chimpanzee ecotourism is becoming increasingly popular and protecting the chimpanzees' health will help to ensure that ecotourism is a sustainable activity.