The question put forward in this study was to pinpoint the impact of the authentic versus non-authentic listening materials on the listening comprehension of Iranian EFL subjects. After random selection, 80 upper-intermediate students from among all language institutes in Khoramshahr and Abadan cities, in Khuzestan province, Iran, took part in this study. The participants participated in two experimental treatment groups. During one semester, they were instructed in listening to authentic radio-tapes and non-authentic listening materials taken from the assorted sources. The results revealed that the participants who were instructed on the basis of authentic radio-tapes had gained a higher degree of listening comprehension and proficiency than non-authentic groups. Given the results of this experiment, the tentative extrapolations could be that some of the assumptions about the futility of teaching authentic listening materials should be rigorously re-examined. That is, the use of aural authentic listening materials in EFL classrooms improves learners’ listening comprehension, and has positive effects on EFL learners.