Dislocation of the knee is a relatively rare injury with modern arthroscopic techniques, operative reconstruction has become the standard of care. The primary aim of this study was to prospectively follow a large, consecutive series of patients with knee dislocation to document associated injuries, surgical treatment, knee function, and knee osteoarthritis (OA) at a minimum of 2 years follow-up. Hundred and twenty-two consecutive patients with a traumatic knee dislocation (Schenck II-IV) were treated at the Oslo University Hospital, Ulleval, between May 1996 and December 2004. Follow-up evaluation of 85 patients consisted of evaluation of knee joint laxity using the KT1000, the Lachman test, the pivot shift test, the reversed pivot shift, the posterior drawer test, the dial test, and the varus-valgus tests compared to the uninjured knee. Knee function was evaluated using the Lysholm score, the Tegner activity level score, the IKDC2000 score, and four single leg hop tests. Radiographic evaluation was performed using the Kellgren & Lawrence classification grade 0-4. Knee function at a minimum of 2 years after surgery disclosed a Lysholm score of a median of 83, a Tegner activity score of 5, and above 83% on all single leg hop tests compared to the uninjured side. Knee function was lower in the patients with a knee dislocation caused by high-energy trauma compared to low energy trauma. Eighty-seven percent had Kellgren & Lawrence grade 2 or higher for the injured knee compared to 35% for the uninjured knee.