Tourism is a spatial phenomenon which involves tourist generating markets, the destination and the movement of tourists from one to another. Although geographic Information Systems (GIS) are widely used in spatial analysis, thir use in tourism planning is limited. In this chapter the potential of GIS in tourism planning is discussed with a special focus on sustainable tourism development of destinations. A thorough literature review is used to reveal trends and patterns in the use of GIS in tourism planning on the base of GIS’ functions. The aim is to reveal the potential from the use of GIS in tourism planning as well as to identify and opportunities for tourism research.