Task-based method of teaching is a type of communicative approach to language teaching all over the world. However, the success of its use depends on teachers’ awareness and approach, and the curriculum in use. To explore these factors in Iran, wherein the curriculum was recently changed, a group of English teachers from schools and centers for language learning was given a questionnaire both before and after the curriculum change. Data analyses revealed that with the old curriculum there was a significant difference between teachers’ knowledge and use of task-based approach. However, at both stages, school teachers considered shortage of time, crowded classrooms, uneven level of language knowledge among learners, and the weaknesses of both teachers and textbooks as the main impediments on the way of using the task-based approach. In other words, although the improvements in textbooks following the curriculum change has led to better understanding of teachers, many other factors remain to be addressed before the use of this approach would bear the desired fruit.