The purpose of this study was to determine the patterns of presentation and early treatment outcomes of anterior cruciate ligament tears at the National Orthopaedic Hospital, Lagos, Nigeria. This was a retrospective cross-sectional study in which the details of all anterior cruciate ligament injuries seen from January 2014 to December 2018 in our facility were noted. The bio-demographic details of the patients were noted as well as the side of the injury, mechanism of injury, type of sporting activity patient was engaged in at the time of injury and the early outcome of treatment of the patients were noted. A total of 19,707 new orthopaedic and musculoskeletal trauma cases were seen in the period. The overall hospital period prevalence rate of anterior cruciate ligament injury in the period was 3.6 per 1000 patients with a gender-specific prevalence rates of 5.7 per 1000 and 1.6 per 1000 for male and female patients respectively. The mean time between injury and presentation was 16 (±21) months with a range of 1-120 months. The commonest aetiology of anterior cruciate ligament injury was non-contact injury during sporting activities. There was a greater involvement of the young and active population in this injury. Sports and road traffic crash related injuries were the commonest injury aetiology in our environment. The early treatment outcomes revealed a significant improvement of the post-operative functional knee scores over the pre-operative functional knee scores.