Abstract
This study is aimed at measuring and summarizing the perceived and expected service quality of passengers of an international airline and to provide the passengers' opinions to the decision makers employing fuzzy logic. The appropriate fuzzification procedure was determined to be the trapezoidal membership function. Using SERVQUAL methodology, the optimal fuzzy interval of the gap scores was determined for each item. The interpretations of these fuzzy intervals were categorized into three areas - optimistic, neutral and pessimistic passenger views - to assist the decision makers in identifying which items of services are satisfactory and which are in need of improvement.