An anterior cruciate ligament (ACL) tear is a severe knee injury, which result in increased knee laxity and often knee instability. An ACL reconstruction (ACLR) is usually recommended to patients who wish to return to pivoting activities and/or in cases of persistent instability during activities of daily living. From a strict surgical perspective, the main goal of an ACLR is to restore knee laxity to a degree as close as possible to that of the native ACL-intact knee. Patients undergoing ACLR are heterogenous in terms of age, gender, and preoperative knee laxity. Time from injury to surgery also varies among patients. Moreover, an ACL injury is almost never isolated. Previous literature has shown that injuries to the menisci and anterolateral structures as well as to the collateral ligaments are very common in conjunction with ACL injuries. Finally, different grafts for ACLR are available and could be chosen depending on several factors. All the abovementioned variables may have an impact on restoration of knee laxity after ACLR. The purpose of this chapter is to provide the reader with an up-to-date overview of the factors affecting knee laxity after ACLR. Strategies and surgical treatments to optimize restoration of knee laxity and ultimately reduce the risk of graft failure are also discussed.