Every year a lot of students have to pass the Prerequisite English Course (PEC) due to their weak performance in the English subtest of university entrance exam. According to the Islamic Azad University (IAU) regulations those entering students who score below 33.3 in this exam are required to take the PEC, the syllabus of which is purely structure-based. If PEC is to continue as the means by which to improve the English proficiency of low-ability students, it must be rigorously evaluated, and if necessary, substantially altered. The main purpose of this experimental study was to see whether PEC could lead to the higher attainment of English language proficiency. 1657 freshmen majoring in 22 different courses at the IAU in Ardabil participated in this study. Following a one-group pretest posttest design, seven different tests were administered to them twice in the form of pretests and posttests. Although very slight improvements were witnessed, the outcome indicated no efficiency on the part of PEC. Therefore, fundamental modifications in both the syllabus and textbook seem inevitable. This monograph can be of help for materials developers as well as programme evaluators.