We meniscectomized 27 knees with meniscal lesions for disabling symptoms after the diagnosis by clinical evaluation and arthrography from January, 1970 to May,1979. Statistical analyses were as follows: 1. Male was affected 2 times more than female. The most meniscal lesions occurred in the age group between 10 and 29 years old (67%). 2. The lateral menisci were affected 2 times than the medial. In the former, the middle segments were affected most frequently and in the latter, the posterior horns. 3. The general diagnosis of torn meniscus for the 27 knees was correct by clinical evaluation for 19(71%), by arthrography for 20 (74%) and by two methods for 24 (88%). 4. In the follow-up study, satisfactory results were obtained in. 79%.