Good monitoring of tourism events is a major factor to secure their sustained development. However, traditional monitoring of tourism events so far has been conducted merely by internal indexes manifestation. This paper suggests a possibility for introducing GIS-based monitoring technique for evaluating tourism events and festivals. Authors arguably show how useful the Geographic Information System would be for monitoring not only internal factors but also external ones. They illustrates by examples how GIS empirically could be utilized to monitor the external factors of tourism events. The monitoring elements considered when applying GIS empirically in this paper include are: analysis of potential market size, evaluation of competitiveness of potential market, time series analysis of tourism information and finally evaluation of potential routes from major market.