This paper describes a summary of an experimental study that I have conducted at the University of Wisconsin – Whitewater in the Fall of 1994. I have taught three out of twenty – four Sections of Intermediate Algebra using Cooperative Learning approach together with Mentors. The goal was to investigate the impact of this approach on students’ performance by comparing the success rate of each Section ( in the Pilot Group ) against 21 Sections in Control Group. The study has shown that the students in two Pilot Sections made a significant improvement in their test scores.