Abstarct: Abstract: Goal of the present research is assessing quality of service at Saman Tajhiz Aria Co. baxsed on quality scale of Parasuraman (expectations and perceptions). Parasuraman model has ٥ aspects including tangibles, responsibility, reliability, assurance, empathy). Whereas importance of courtesy; this factor is added to model as well. Statistical universe of the present research is ١٥٠ customers of Saman Tajhiz Aria Co. In order to collect data it was used from questionnaire and validity of questionnaire was calculated at ٧٨%. In order to test hypothesis, it was used from couple comparison statistical test and in order to prioritize aspects of quality of service, it was used from Freedman test. Results of research indicate that performance of company with respect to responsibility and courtesy is higher than customer expectation and factors including tangibles, reliability, assurance and courtesy are less than expectation.