The study intended to measure the quality of the services in Wattaya Campus Central Library based on a modified LibQUAL+ survey that measures the quality of the library services which determines the differences between users' expectations and perceptions. A stratified random sample that is constituted of the undergraduates and faculty members of Muscat Nursing Institute (MNI) and the Institute of Health Sciences (IHS) was used in the study. The total number of the participants was 309 (n=309). A modified, Arabic translated format of LibQUALt survey, which was developed by the Association of Research Libraries, was adopted in the study. LibQUAL+ survey measures the services quality based on the differences between the mean scores of the users' perceived and expected level of services. It tested four dimensions of service quality which were: Affect of Service, Library as a Place, Information Control and Access to Information. The most important results of the study were: 1. All attributes of service quality in the Central Library did not meet the users' expectations, but that does not mean it lacks quality. 2. The Information Control and Library as a Place dimensions were the most problematic, while Affect of Service dimension was the least problematic amongst others. 3. The most important issues that need improvement were: modem equipment or tools that ease the access to information, library space, and availability of remote access to electronic information respectively. 4. There were statistically significant differences between faculty and students in their perception about the library services. In particular, they differ in their expectations about three service dimensions. Moreover, there were significant differences in Affect of Service and Information Control between the respondents from different disciplines. 5. WCCL's most noteworthy performance was in the area of Affect of Service dimension, followed by Access to Information, then Library as a Place and finally the least performance was scored for Information Control. In light of these results, the study came out with some recommendations as follows: 1. To implement an annual strategic plan for the evaluation of the library services. 2. To review the current acquisition and circulation policies followed in the Central Library, and change them substantially. 3. To activate the role of the "Advisory Committee" in order to enhance the services' quality at the Central Library and its branches. 4. To implement the latest LibQUAL+ model in the Central Library and its branches every two years, and to subscribe in the electronic version of LibQUAL+.