Reports of ring menisci are rare. This article describes a case of a congenital lateral ring meniscus and includes a literature review. The anatomy of the menisci of various vertebrates is described with an attempt to discuss the possible origin of the anomaly. Although ring menisci are asymptomatic, they are clinically significant in that they need to be differentiated from old bucket-handle tears. It is also easy to fail to visualize the intercondylar bridge between the two "horns" with conventional magnetic resonance imaging.