Introduction: The reference section is one of the most important parts in every library. Moreover, reference services represent all the attempts performed in a library. Since libraries primarily aim to satisfy users' information needs, knowing that the effects of information technologies (IT) on their services seems essential. Therefore, this study manly tried to assess the effects of IT on reference services provided by university libraries.Methods: This survey covered all librarians of central libraries associated with Ministry of Science, Research and Technology (n=66) in 2008. A researcher-developed questionnaire containing 60 questions whose validity was confirmed by library and information sciences experts. The reliability of the questionnaire was calculated by internal consistency (Cranach's alpha=0.96). This study evaluated different technologies including online public access catalogs (OPACs), databases, email, and web. It also included reference services such as individual instruction, group instruction, readers' advisory services, bibliotherapy, term-paper counseling, selective dissemination of information, ready-reference question, bibliographic verification, interlibrary loan, referral services, and research questions.Results: Based on the findings of this study, reference librarians of university libraries did not believe OPAC, databases, email, and web to fully satisfy users' needs. This research also showed significant differences between the effects of OPAC and databases, OPAC and web, databases and web, and email and web. However, there were not significant differences between the effects of OPAC and email or databases and email. In addition, among the studied technologies, the effect of web on reference services was highest and the effect of OPAC was the lowest.Conclusion: Due to insufficient computer-related knowledge, librarians still see reference services as necessary.