Authors experienced 44 patients, 51 cases of discoid meniscus among 154 patients of meniscus injury in the 376 patients of IDK for the diagnosis and treatment from September 1983 to January 1990 at Guro Hospital, the Korea University College of Medicine. Through over 1 year follow-up period after total or partial meniscectomy for the treatment of the disceid meniscus, we obtained the results as follows;1. The commonest age group was the second decade 24 cases (47%) and the ratio of man and woman is 1.3:l. 2. The average symptom duration was 32 months ranged from 1 week to 10 years. And the major symptoms for meniscectomy were pain in 45 cases (88% ), loud snapping in 40 cases (78% ), locking in 15 cases (29% ) etc. 3. The treatments we and done were arthrotomy and total meniscectomy 16 cases (31.3%), arthrotomy and partial meniscectomy 20 cases (39.2%), arthroscopic total meniscectomy 1 case (1.9%), and arthroscopic partial meniscectomy 14 cases (27.4%). 4. The operative findings were intact meniscus 14 cases (27.4%), longitudinal tear 16 cases (31.3 %), transverse tear 6 cases (11.7%), horizontal tear 5 cases (9.8%), combined tear 10 cases (19.6% ). 5. The complications followed by meniscectomy were pain 20 cases (38%), swelling 15 cases (28. 5%) locking 5 cases (9.8% ), weakness 5 cases (9.8%) etc. 6. The findings in radiological study through average 18 months follow-up were joint space narrowing 20 cases (39%), femoral condylar flattening 18 cases (35%), and tibia sclecrosis 20 cases (39% ), etc. 7. Above clinical and radiological resuts suggested that meniscectomy of the discoid meniscus was not enough to obtain a satisfactory result, and some kinds of conservative treatment should be considered.