Background & objectives: Today, the concept of q uality of services is particularly important in health care and customer satisfaction can be defined by comparing the expectations of the services with perception of provided services. The aim of this study was to evaluate the quality of services provided for outpatients in clinic of Ardebil city based on the SERVQUAL model.

  Methods: This descriptive study was conducted on 650 patients referred to outpatient clinic since July to September 201 3 using a standardized SERVQUAL questionnaire (1988 ) with confirmed reliability and validity. The paired t-test and Friedman test were used for analysis of data by SPSS software.

  Results: 56.1 % of respondents were male and 43.9 % of them were female . The mean age of patients was 33 ± 11.91 , 68.9 % of patients were in Ardabil and 27.3 % of them had bachelor's or higher. The results showed that there is a significant difference between perceptions and expectations of the patients about five dimensions of the service quality (tangibility, reliability, assurance, responsiveness, and empathy) in the studied clinic (P< 0.001). The highest mean gap and minimum gap were related to empathy and assurance, respectively.

  Conclusion: Regarding to observed differences in quality , the managers and also planners have to evaluate their performance more accurately in order to have better planning for future actions. In fact, any efforts to reduce the gap between expectation and perception of patients result in greater satisfaction, loyalty and further visits to organizations.