In the treatment of meniscal injury of the knee joint, it has been known that the result of partial meniscectomy to prevent degenerative change of the knee joint after meniscectomy. However the result of lateral discoid meniscectomy is controversial between partial and total meniscectomy. In the treatment of lateral discoid meniscal injury, Fujikawa and Dickhaut reported the better results with partial meniscectomy than total resection, but Ikeuchi and Kobayashi reported the better results with total meniscectomy. The purpose of this paper is to compare the results of arthroscopic partial and total meniscectomy. Five hundred ninety-five patients with meniscal injury was treated by meniscectomy between January, 1983 and December, 1994 at the department of orthopaedic surgery, Soonchunhyang Univ. Hospital. 119 patients of all were done lateral discoid meniscectomy had no other combined findings. Wr wrre able to follow up 42 patients(44 cases) of 84 patients with interview and/or questionnaire. WR analysed the 44 cases and summarized the results as follow: 1) A discoid lateral meniscus was presented in 20.0% of all meniscal resection. 2) Postoperative click sound was presented in 7 cases of 25 cases(28.0%) with partial meniscectomy and in 5 cases of 19 cases(26.3%) with total meniscectomy. Giving way was presented in 2 cases(8.0%), 1 case(5.3%) and Locking in 1 case(4.0%), 0case(0.0%) respectively. 3) In the post operative. Pain, no pain and mild pain were presented in 88.0% of partial meniscectomy and in 94.8% of total meniscectomy. 4) In the degree of activity level, “same before symptoms was developed(no symptom)”. was presented in 84.0% of partial meniscectomy and in 84.2% of total meniscectomy. 5) In the return to work, all patients returned to original job with/without limitation. 6) In the knee rating scale of Ikeuch, excellent or good was presented 72.0% of partial meniscectomy and in 89.5% of total meniscectomy. 7) Roentgenologic degenerative changes were more presented after total than partial meniscectomy. We concluded that the total meniscectomy is better than the partial meniscectomy in the symptom and functional results, but long term follow up secondary degenerative change must be followed.