This paper aims to gift the results of a survey conducted to see the effective use of online Public Access Catalogs (OPAC) at the library of Jeppiaar Maamallan Engineering College in Chennai. The paper examines the result from a questionnaire based survey conducted at the library. 50 samples of the form were distributed in a random way between the employees of Jeppiaar Maamallan Engineering College in Chennai out of which 48 completed and valid questionnaires (96.00 %) were received for analysis. The information received from the respondents through these questionnaires was analyzed. Thus, the study clearly highlighted the requirement for associate degree education programme module for users to market the effective use of OPAC. An effort is formed through this study to gift the difficulties Janus-faced by users at engineering college libraries, in looking for data victimization OPAC. This paper provides helpful empirical proof for librarians and therefore the analysis community on the usage of OPAC in libraries of engineering colleges. The results of this study are going to be helpful for librarians at Jeppiaar Maamallan Engineering College in Chennai and additionally to different librarians around the state and country. This paper provides original information from library finish users in engineering college, relating to their expertise whiles victimization OPAC.