There are different factors affecting reading strategy use and reading performance in L1 and L2 for texts of different genres. This study attempts to find out if general English proficiency level affects reading strategy use and reading performance in L1 and L2 (EGP or English for General Purposes and ESP or English for Specific Purposes) reading tasks. To this purpose, thirty nine tertiary level students who were freshmen and sophomores at the University of Mazandaran, majoring in accounting, mathematics and computer Engineering took part in this study. They were divided into two groups of high and low based on general English proficiency levels. Then, they were given tests of reading in L1, EGP and ESP followed by reading strategies questionnaire as a retrospective measure of their reading behavior. The obtained results indicated that the students of high proficiency level did not differ significantly from the students of low proficiency level in reading strategy use and reading ability in Persian, EGP and ESP strategy use. It is concluded that reading strategy use and reading performance in L1 (Persian), EGP and ESP are not very much predictable by one factor, namely L2 general proficiency level and the contribution of other factors, such as motivation and attitude toward reading L1 and L2 reading need to be considered.
