This article discusses the anterolateral ligament (ALL) of the knee, which was first identified by Paul Segond in 1879. It provides an anatomical description of the ALL, its three regions (femoral, middle, and tibial), and the prevalence of injuries to these areas. The article highlights the association between ALL injuries and anterior cruciate ligament (ACL) tears, emphasizing the challenges of detecting ALL injuries via MRI and the importance of recognizing related signs, such as Segond fractures, in the diagnosis process.