Travelling is a risky business. One of the risks is to aquire a tropical infectious disease and import this disease into the home country. To gain insight in the relation between travelling and tropical diseases data of various sources have been collected. Travellers' diarrhoea and fever are the most frequent complaints travellers suffer from. A study showed that 15% of the travellers remained ill after returning home. In 1990, 800 cases of so-called import diseases were reported at the Inspectorate of Health. The registration probably is not complete. Import diseases regularly seen in the Netherlands are dysenteria bacillaris, typhoid fever, hepatitis A, malaria and tuberculosis. The transmission route and pathology of these diseases is briefly discussed. Also the occurrences in the Netherlands from 1950 until now is given. Possible preventive measures are vaccination, chemoprophylactic medicine and preventive behaviour. A study showed that only 50% of the Dutch travellers took preventive measures and that this percentage among non-Dutch inhabitants was much lower. It is important to improve travel health advice. The government, travel agencies, travel health centers and migration organisations must cooperate to achieve this goal. Several more data are necessary to discuss the topic of import diseases. A more complete view of the problems could lead to a better vaccination level and health care advice for travellers.