The purpose of this study was to observe the change of the meniscal lesions, which are conservable by suture or simply by leaving-in-place within the frame of operated anterior instability. Forty-six knees which had been operated by the free transplant of bone-patellar tendon-bone, presented the associated lesions of conservable meniscus. These lesions were treated by suture of the meniscus in 15 cases and left in place in 31 cases. The programme of rehabilitation was the same in the two groups. All the patients have been followed-up for 26 months in average (12-40 months). In the group of meniscal suture, only one secondary meniscectomy was carried out. 8 patients presented moderate pain on the corresponding femorotibial joint line and 5/13 of the sportive patients recovered to the same level of activity. In the group of leaving-in-place, no meniscectomy has been carried out. Only 4 patients complained of pain and 23/27 recovered to the same activity level. The arthrographic and arthroscopic observations have been carried out in 23 cases. They confirmed the cicatrization of the sutured meniscus but also showed the possibility of total or partial cicatrization of the lesions left in place (12 on 13). The authors conclude that the peripheral meniscal lesions associated with the operation of the chronic anterior instability do not always require suture. The abstention on the meniscal lesion is possible if it is limited on the posterior segment: Then the functional results seem better.