This study applies the Multiple Criteria Decision Making (MCDM) to evaluate the service quality of some Turkish hospitals. In general the service quality has abstract properties, which mean that using the previously known measurement approach is insufficient. It is for this reason that the fuzzy set theory is adopted as a research template. In Istanbul, Turkey, there are four B class hospitals classed as private hospitals that are covered by the Social Security Institution (SSI) and for which we propose to represent the service performance measurement using triangular fuzzy numbers. In this study, importance weights of performance criteria are found with AHP. Then, the Multiple Criteria Decision Making methods TOPSIS and Yager's min-max approach are applied to find and rank the crisp performance values. In a second step, an aggregation of performance criteria with OWA and Compensatory AND operators are looked at instead of the TOPSIS method and min-max approach. Thereby numerical applications are supplied by the four methods and the obtained results are compared. (C) 2014 Elsevier B.V. All rights reserved.