The research aims at measuring the effectiveness of the use of cooperative learning compared to the traditional method in teaching English courses for students of the Deanship of Preparatory Year and Supporting Studies, Imam Abdulrahman Bin Faisal University, Saudi Arabia. It is hypothesized that cooperative learning is more effective than traditional teaching in learning English and developing better academic achievement. The study involved 60 advanced students apportioned into two groups: 30 in the experimental group studying the English language course through cooperative learning and 30 in the control group studying the same course through the traditional method. After the teaching period, which lasted seven lectures at a rate of a lecture per week, the research instrument is applied to both groups. The data extracted from the pre- and posttests are processed statistically using the independent data student t test to verify the validity of the research hypotheses. The data are also subjected to the equation of improvement ratios in order to find the differences between the average test scores of the two groups' pre- and post-tests. The results demonstrate the validity of the research hypothesis.