Human mobility has increased tremendously during the last century and people are moving today all over the planet. It is estimated, that every year more than 50 million people cross international borders to tropical or subtropical destinations. Here they encounter different cultures, social habits and economic standards, and, of the utmost importance, a different microbiological enviroment. The frequent inconsiderate risky behavior of nonimmune travellers may cause serious infections to occur. The health protection of travellers consists of awareness of travel-related infectious diseases, uptake of pretravel health advice, vaccinations and malaria prophylactic measures.