Purpose To summarize and discuss the current knowledge on posterior lateral meniscus root tears. Methods A comprehensive review of the MEDLINE database was carried out to identify relevant articles using different keywords (e.g. “meniscus root”, “root tear”, “meniscus avulsion”, “radial tear” and “lateral meniscus”). The reference lists of the reviewed articles were searched for additional relevant articles. Results Posterior lateral meniscus root tears are found in 7–12 % of patients with a tear of the anterior cruciate ligament (ACL). Biomechanical studies have found an increase in lateral compartment contact pressure of approximately 50 % after creation of a posterior lateral meniscus root tear. There is some evidence that the biomechanical consequences of these injuries are significantly influenced by the presence and integrity of the meniscofemoral ligaments. Clinical studies have found encouraging results after repair of posterior lateral meniscus root tears. Whether root repair can prevent the development of osteoarthritis is currently unknown. Conclusion A posterior lateral meniscus root tear is a clinical relevant but most likely underrecognized concomitant injury in patients with a tear of the ACL. This article may support clinicians in diagnosing and treating this unique type of meniscus tear. Level of evidence V.