Purpose -The purpose of this research is to study the determinant factors in the acceptance of information technology (IT) by librarians in the libraries of engineering faculties of public universities in Tehran. Design/methodology/approach -The Technology Acceptance Model (TAM) is used as the research framework and the applicability of this model on the research population is studied. The constructs of TAM include its perceived usefulness, perceived ease of use, attitude toward use, and the intention to use IT. These are the independent variables that affect the dependent variable of IT use. The first six hypotheses of the research have been based on inter-relationships between each pair of variables in the TAM. The applicability of the TAM model on the population of librarians is the seventh hypothesis. The survey method was applied for collecting data, using a questionnaire. The studied population included 160 librarians and the questionnaire was sent to all of them. Findings -The research findings indicate that all independent variables in the framework of TAM affect the acceptance of IT, but the final results (R ¼ 0.033 for Model) indicate that the applicability of the TAM model to study this group is weak. Originality/value -There is a lack of research of the acceptance of IT using the TAM model in Iranian organizations and libraries, as well as in libraries and in library science around the world.