The technique of the arthroscopic total meniscectomy of discoid meniscus is very difficult. Ikeuchi(1982) reported a technique of arthroscopic total meniscectomy of the lateral discoid meniscus by removal of 2/3 of the anterior part of the meniscus first and then by morselization. The purpose of this paper is to report a technique of arthroscopic total meniscectomy of the lateral discoid meniscus as a whole. During the period from October 1982 to October 1984, we had 12 experiences of arthroscopic total meniscectomy of the discoid meniscus and found good results, that is, little postoperative pain, short period of hospitalization and early restoration of joint motion without physical therapy. Complications are 3 cases of symptomless slight lateral instability and 4 cases of hemarthrosis.