Air transportation, which provides fast, reliable and comfortable transportation, enables the different geographical areas to be closer, and thus it causes to develop the commercial, touristic and social life and to meet different cultures. Privatization, commercialism, liberalization concepts along with the rapid developments of economic and social transformations has not only influenced the air carrier system but also airports which are the most important elements of the air transportation system. In the frame of these new concepts, airports which are the ones of the basic service sector investments are transformed from the public investments providing only transportation needs, to the investments making trade and earning profits by providing various type of services. Some of these airports have big goals such as being international hubs which supply much more gains not only for themselves but also for their region and countries. By all these transformations and goals, in order to go further and better levels, in the sense of operation of the airports, evaluating the internal performances of airports and benchmarking them with similar airports should be performed, then necessary improvements and arrangements in the direction of the performance results should be applied. At the airports, there are different customers and interest groups which have different expectations from the airports. These are mainly passengers, airlines, airport operators and regional residents. In this study, arising from the idea of "airports' performances should be represented not only by the performance levels of the expectations of one customer group, but also those of all customer or interest groups' as well", a customer oriented performance model composed of the service, operational and technical, financial and environmental criteria representing the expectations of passengers, airlines, airport operators and regional residents, has been developed for airports. This model enables the airports' internal performances to be evaluated and their performances to be compared with those of the other airports. With this model, it is aimed to stress that operating the airports at the highest performance levels depend on the activities which require multi responsibilities for reaching the goals. Because of the fact that there are many criteria to be evaluated for the model and the data required for these criteria are both objective and subjective, it is decided that the most suitable approach is Fuzzy Multi-Criteria Decision Making. In evaluation of the model, "Fuzzy TOPSIS" and "Fuzzy Simple Additive Weighting" methods were used and for Fuzzy TOPSIS method, Chen and Hwang's right and left scoring ranking, for Fuzzy Simple Additive Weighting method, Abdel- Kader and Dugdale 's and Liou and Wang's ranking methods were applied. Weighting of the criteria and rating of the airports have been performed directly by customers and interest groups. In this study, two case studies were performed. The first one was the comparison of Istanbul Atatürk, Izmir Adnan Menderes, Bodrum, Dalaman and Antalya Airports in Turkey. The results of general evaluations of this case study demonstrate that the performances of airports which their international terminals are operated by private sector, are higher than those of the airports operated by public sector. Also, the results demonstrate that the rate of international passengers affect the financial performance of airports. The second case study is the comparisons of performances of Istanbul Atatürk, Athens Venizelos, Munich and Vienna airports. At this practice, the service and operation and technical submodels were integrated as a general model and it aims to test the competitive strength of Atatürk airport against to Athens Venizelos, Munih, Vienna airports. At the second case study, two comparison were performed. At comparison among Istanbul Atatürk, Vienna and Munich Airports, Istanbul Atatürk Airport has the lowest performance score. At the second comparison, the performance of Atatürk Airport was compared with that of Athens Venizelos Airport. As seen in the result, their scores are very close. Istanbul Atatürk and Athens Airports serve in the same geographic region and their strategic goals are being international hub. In this way, the winning airport will be the one which will make the required investment and utilize the marketing techniques created by their skills to develop its performance. In this study, the importance of the evaluation of airports' performance has been stressed and proposed an "Airports' Performance Monitoring and Developing Organization" to be established by Civil Aviation Authorities.