This study aims to identify the reality of cataloguing in academic and public libraries in the Sultanate of Oman, through identifying the role of information and communication technology in cataloguing services in libraries, and their impact in facilitating procedures and quality control. This study is looking forward to have a good effect in the services of libraries. The study adopted the descriptive analytical approach to describe the reality of cataloguing in academic and public libraries in the Sultanate of Oman. The study depends on questionnaires to answer the questions of the study. The study population consisted of staff who are working in cataloguing services in Omani libraries, which included 7 libraries: three public libraries, and four academic libraries. The sample included 34 catalogers in all libraries. The study came up with a number of findings. Here are some of the most important ones: all the libraries use Anglo-American Cataloguing Rules (AACR2). Also, they are using Shaaban Khalifa Arabic Subject Headings for Arabic resources. In addition, they are all using the list of Subject Headings of Library of Congress for non-Arabic resources. Also, the study sample uses electronic tools for cataloguing, such as the Electronic Plan of Library of Congress Classification, plan of Dewey Decimal Classification, the LC Cataloguer Desktop, rules of Resource Description and Access Points ( RDA) and Periodicals Guide UlrichWeb. The study found that 97% of the study sample, who are working in cataloguing, are graduates from Cataloging Departments, which means they are professionals. It also found that 87% from the study sample have knowledge on using Anglo-American Cataloguing Rules (AACR2). The same percentage, 87% applies for MARC 21. Using Library of Congress cataloguer desktop has got the percentage of 64%. The degree of knowledge of the rules of cataloguing using the new resource description and access points (RDA) is 32%. The degree of knowledge of the tools of electronic cataloging using objective analysis in Catalogingcalculator website is 71%. Knowledge on Classification and subject heading LC got the percentage of 68%. On the other hand, the percentage of those who use electronic Dewey Decimal Classification is 33%. The most used OPAC catalogue in the sample of the study is the copy cataloguing. 54% of the study sample is using the Catalogue of Sultan Qaboos University libraries for Arabic books and 76% are using the library of Congress catalogue for non-Arabic books. The opinions of the cataloguers varied regarding maintaining quality control in cataloguing. 23% of the sample prefer cooperative cataloguing . 23% support the proposal of establishing Cataloguing and Classification Committee under Omani Association for Libraries. In light of these results the study proposed a number of recommendations: developing a written cataloguing policy for all libraries, guiding Omani libraries toward cooperative cataloguing systems, using the tools of electronic cataloguing, taking into consideration the quality of cataloguing and adopting the proposal of National Cataloguing Union project.