The aim of this research is to study the quality of services in the public libraries of Tabriz. This applied research was conducted with a quantitative approach and a survey method. The statistical population of the study was 37931 members of the Public Libraries of Tabriz and the sample size was 380 cases that were selected by stratified random sampling. The data collection tool was the standard LIBQUAL questionnaire and its reliability in the present study based on Cronbach's alpha was 0.93. In order to answer the questions and hypotheses, descriptive and inferential statistics were used using SPSS 24 statistical software. In general, in the three dimensions of LIBQUAL, the average level of minimum expectations of respondents was 4.39, the average level of received services was 5.70 and the average level of maximum expectations was 6.68. The difference between users' expectations and the level of received services in each dimension of the LIBQUAL was not higher than of the maximum expectations. The results of paired t-test confirmed the existence of a significant difference between the maximum expectations and the level of received services by users and also the existence of a significant difference between the minimum expectations and the level of received services by users in all dimensions of the LIBQUAL. It can be concluded that although the libraries have been able to meet the minimum expectations of the users in all cases partly, but the maximum expectations of the users have not been met yet.