Postoperative rehabilitation programs are believed to influence clinical outcome. The purpose of this paper was to outline the evolution of postoperative rehabilitation following anterior cruciate ligament reconstruction. Because of the controversy surrounding accelerated ACL rehabilitation and the concept of gaining terminal knee extension immediately following reconstruction, the authors felt justified in carrying out a retrospective comparison of traditional rehabilitation versus an accelerated approach. The objective variables under consideration included range of motion, isokinetic strength, and ligamentous stability. Results showed that active and passive range of motion, including hyperextension, returned more quickly and more fully in the accelerated group. Ligamentous stability was found to be equal to or better in the accelerated group despite a more aggressive rehabilitation approach. The results of this study indicated that an accelerated rehabilitation program following ACL reconstruction resulted in improved range of motion and strength gains without compromising stability. J Orthop Sports Phys Ther 1992;15(6):309-316.