Revision ACL surgery is a technically demanding enterprise that requires meticulous preoperative planning and tempered postoperative expectations on the patient's part. Despite the complexities of the procedure, it is becoming more common as an increasing number of primary ACL reconstructions are being performed, expanding the pool of patients at risk for failure. Candidates for revision surgery should be selected carefully, focusing on those patients with recurrent instability rather than pain as their primary complaint. A thorough history and physical examination is essential, taking care to identify additional patholaxity that might contribute to a failed ACL reconstruction. To optimize outcomes, surgeons must take care to avoid common pitfalls in index and revision procedures. Femoral and tibial tunnels should be positioned anatomically, and staged bone grafting procedures should be considered if revision graft fixation may be compromised by tunnel defects. The type of graft must be carefully selected, appropriately tensioned, and securely fixed. Surgeons should have a number of techniques and instruments at their disposal for performing each of these steps, as the highly variable presentation of failed ACL reconstructions demands a versatile approach. Ultimately, with cautious rehabilitation, these techniques will allow for restoration of knee stability and, in many cases, an improvement in activity level.