PurposeConsidering the important role of public libraries in providing health information service as well as user feedback in improving the quality of health information services, the purpose of this study is to evaluate the quality of health information service in public libraries of Hamadan, Iran, on the basis of the modified LibQUAL modelDesign/methodology/approachThis practical research was conducted in an analytic-survey method. The statistical population consists of all members of public libraries of Hamadan over 18 years old (12,237 people), and the sample size is calculated to be 373 people. The stratified sampling method was used, and within each class, a convenience sampling method was used. The modified LibQUAL questionnaire was used to gather data. For checking normality of data distribution, the Kolmogorov–Smirnov test and for analyzing date, descriptive statistics and also Chi-square and Wilcoxon tests were applied using SPSS 25.FindingsThe users' minimum level of public libraries in all three dimensions is an average level. The users' desired level of “information control” is higher than other dimensions. The users' perceived level in dimensions of “human resources” and “information control” is high level, while users' perceived level in “educational service” is an “average” level. There is a superiority gap between desired and perceived level in all dimensions, but the adequacy gap was seen only in the dimension of “educational service.”Research limitations/implicationsIn this study, the quality of health information services provided in public libraries is evaluated by the LibQUAL model.Practical implicationsThe results of this research can help managers and librarians of public libraries in measuring the quality of health information services and improving the quality of services provided by libraries. Besides, they can take a more accurate planning and pathologic approach, to eliminate the gap between minimum and desired expectations of users and libraries’ real services.Originality/valueIn this study, the quality of health information services provided in public libraries is evaluated by LibQUAL tool.