A prospective study of repaired vertical peripheral tears of the meniscus in fifty patients (nine women and forty-one men) was carried out from January 1977 to June 1980. All tears were confirmed preoperatively by arthroscopy. Forty-three medial and seven lateral menisci were repaired. Fifteen tears were treated within two weeks and thirty-five were operated on as long as seven years after injury. Only eight patients had a meniscal tear that was not accompanied by injuries of either the anterior cruciate ligament or the collateral ligaments, or both. At a mean follow-up of eighteen months (range, six to thirty-nine months), forty-two patients (84 per cent) had clinically apparent healing of the sutured meniscal tear. Repeat arthroscopy was done in twenty-seven (64 per cent) of these patients, four to twenty-nine months (mean, twelve months) after the operation. The arthroscopy proved that all of these repaired tears had healed. Eight patients had a second tear after the initial repair: four were reruptures at the sutured area and four were new ruptures in another area of the meniscus and were associated with fresh trauma. All of these patients subsequently had an arthroscopic meniscectomy.