Purpose The purpose of this systematic review was to address the treatment of multiligament knee injuries, specifically ( 1 ) surgical versus nonoperative treatment, ( 2 ) repair versus reconstruction of injured ligamentous structures, and ( 3 ) early versus late surgery of damaged ligaments. Methods Two independent reviewers performed a search on PubMed from 1966 to August 2007 using the terms “knee dislocation,” “multiple ligament–injured knee,” and “multiligament knee reconstruction.” Study inclusion criteria were ( 1 ) levels I to IV evidence, ( 2 ) “multiligament” defined as disruption of at least 2 of the 4 major knee ligaments, ( 3 ) measures of functional and clinical outcome, and ( 4 ) minimum of 12 months' follow-up, with a mean of at least 24 months. Results Four studies compared surgical treatment with nonoperative treatment. There was a higher percentage of excellent/good International Knee Documentation Committee (IKDC) scores (58% v 20%) in surgically treated patients, as well as higher rates for return to work (72% v 52%) and return to full sport (29% v 10%). Two studies compared repair with reconstruction of damaged structures, with similar mean Lysholm scores (88 v 87) and excellent/good IKDC scores (51% v 48%). However, repair of the posterolateral corner had a higher failure rate (37% v 9%). Similarly, repair of the cruciates yielded decreased stability and range of motion and a lower return to preinjury activity levels (0% v 33%). There were 5 studies comparing early surgery (≤3 weeks) with late surgery. Early treatment resulted in higher mean Lysholm scores (90 v 82) and a higher percentage of excellent/good IKDC scores (47% v 31%), as well as higher sports activity scores (89 v 69) on the Knee Outcome Survey. Conclusions Our review suggests that early operative treatment of the multiligament-injured knee yields improved functional and clinical outcomes compared with nonoperative management or delayed surgery. Repair of the posterolateral corner may yield higher revision rates compared with reconstruction.