Although Task-Based Instruction (TBI) has received large attention on the part of English practitioners throughout the world, it seems that there is yet a huge gap between the Iranian EFL teachers’ perceptions and practices in implementing it in real classes. Hence, this study set out to unearth the possible sources of difficulties in using TBI in EFL classes. To meet the goals, a total of 120 male and female EFL teachers were selected through stratified random sampling from Iran language institute (ILI) branches in Tehran, Iran. After critically reviewing the literature and using a flow chart technique, a questionnaire including 20 items was developed, piloted, and distributed among the participants. Then, the collected data were analyzed through the Confirmatory Factor Analysis (CFA). Results indicated that three main factors, namely lack of appropriate assessment methods , cultural difference , and efficacy of the method received the utmost significance from the EFL teachers’ perspectives that have led to not using TBI. In the end, the implications of the findings were discussed for different stakeholders.
