The importance of input and exposure to simplified language for low level learners has been the focus of a lot of attention as a way to facilitate the process of language learning and acquisition. One way to help such learners is to have them read many simplified texts in the Language, a method which is called extensive reading. Many studies have shown the effectiveness of such programs in improving learners' reading proficiency. The main goal of the present study was to examine the effects of Extensive Reading Project on Iranian low level learners. To find its effects, of 67 EFL students who had failed their first reading course, 40 students were selected randomly and were divided randomly into one experimental and one control group. A standard reading proficiency test (pre-test) confirmed the homogeneity of both groups. Then during a program which took ten weeks to be accomplished, participants of the experimental group were asked to read ten interesting stories in English as a part of their reading class, while the members of control group continued their traditional reading class. At the end, the same standard reading proficiency test, as post-test, was introduced to both control and experimental groups. The obtained results revealed that there was a significant difference between the performances of both groups; in other words, extensive reading (ER) had a positive effect on the reading proficiency achievement of low level EFL students.