A review of the literature and experience with three cases demonstrates that, rarely, a painful knee in a young person may be due to the presence of an ossicle in a meniscus. Roentgenographically, the ossicle may be misinterpreted as a loose body. Awareness, however, of the possibility that there is a bone in a meniscus may avert a fruitless search for the loose body. Excision of the affected, but externally intact, semilunar cartilage uniformly results in relief of symptoms from the knee.