Discoid semilunar cartilage is an abnormality in which the meniscus is discoid rather than semilunar, and first reported by Young of Glasgow in 1889. 13 cases of discoid semilunar cartilages which were experienced at the Department of Orthopedic Surgery, College of medicine, Seoul National University from Jan. 1956 till Aug. 1972 are reported with review of literature. 1) The incidence was remarkable higher in the male than in the female as 11 versus 2, and higher in the age group of second decade (Average 16.4 year old). 2) Most common site was lateral meniscus, and bilateral discoid meniscus were 3 cases. 3) 3 cases out of 13 cases had complicated rupture of semilunar cartilage, and one case had cyst of the meniscus. 4) Meniscectomy were performed in all cases with successful outcome.