Libraries face many challenges due to competitive enviornment from vendors, publishers, mass media, online services and internet.User''s expectations have increased due to advanced information technology and information explosion.In order to meet these challenges libraries need to assess their SQ to know whether they are meeting user?s needs and expectations or not. The purpose of this study was to measure service quality of academic libraries of a major university from students'' perspectives and to determine libraries'' own performance towards meeting users'' expectations. Research settings of the study were University of the Punjab''s academic libraries, excluding the main library. A survey method was chosen as a method of investigation and a modified SERVQUAL questionnaire was used to explore users'' desired and perceived service levels.The sample of the study was selected using stratified random sampling through proportional allocation. The results revealed that users'' expectations were high as compared to their perceptions. The overall service quality and satisfaction of the university''s libraries was found to be somewhat good.