Hippocrates already noted that geographical factors such as climate, relief, geology but also settlement patterns had influenced the distribution of diseases. The task of medical geography is to investigate the associations between geographical factors and diseases. Thereby, geographic techniques and concepts are applied on health problems. Of particular importance is the mapping of diseases whose causes are environmental-related. In addition, epidemiological, ecological but also social scientific studies play an important part in the investigation of the associations between geographical factors and diseases. In order to understand the associations between the spatial distribution of diseases and environmental exposures, geographic information systems as well as statistical analyses have recently become more important. Some authors regard medical geography merely as supporting discipline of medicine. Nevertheless, as men and environment future and as they play an important part in the diffusion of diseases being regarded as defeated, medical geography will play an important part concerning medical questions. Especially travel medicine will rely on geographic knowledge, if a patient has to be consulted who plans to travel to an unknown country of which knowledge on the geographical distribution and ecology of diseases will be necessary.