Wayfinding is one of the most important factors to be considered for overall passenger satisfaction in an airport terminal. Martel and Senevirathne (1990) found way finding information to be the most important service quality attribute for circulation. Furthermore, research related to overall service quality by Adikariwattage (2015) and Correia, Wirasinghe, and de Barros (2008) underscore the importance of circulation signage as one of the most important attributes at airport terminals. Larger and more complex the facility is more consideration need to be given for providing facilities for wayfinding. Most airport operators follow the practice of qualitatively evaluating wayfinding level of service, which is highly subjective to user profile and limited in use for planning and design purposes. Purpose of this research is to apply the visibility index (VI) method, as a quantitative technique to evaluate wayfinding level of service for departing passengers at Bandaranaike International Airport (BIA), Sri Lanka. A set of level of service grades are derived for evaluating wayfinding level of service at BIA using the method proposed by Dada (1997). Calculated VI values are used in an importance performance analysis in order to identify strengths and weakness in the current wayfinding facilities at BIA