Background and Aim: Organization and utilization of non-book materials is an essential issue; therefore, this study aims to evaluate the organization of non-book materials in central libraries of selected universities of Tehran.

 Materials and Methods: The present survey has been conducted as a cross-sectional, descriptive study in 2012. The population consisted of central libraries of selected universities of Tehran. Data gathering instrument was a questionnaire divided into three sections. The validity of the questionnaire was checked by the professionals of the field and its reliability turned out to be 88% using Cronbach's alpha test. Data analysis was performed with SPSS and excel. The findings were presented using descriptive and analytic statistics.

 Results: Most of non-book cataloged and indexed materials are theses and compact discs (CDs). Most of the libraries of this study use the Library of Congress Classification System for organizing their materials, and all of them (100%) apply Anglo-American rules for cataloging. Regarding the staff of libraries, 40 (95%) had academic degrees in library studies. As to their familiarity with OPEC, 4 libraries ( 80%) were familiar with Library of Congress (LC) and 3 ( 60%) were familiar with National Library of Iran. NOSA software was used in 4 ( 80%) libraries , and Windows operating system in all (100%).

  Conclusion: Based on the results of the present study, it can be concluded that the organization of non-book materials in these libraries is not as desired.