78 patients were randomized to undergo either single-bundle or double-bundle anterior cruciate ligament (ACL) reconstruction using a semitendinosus tendon. The purpose of the study was to compare these two reconstruction techniques over the long-term (max 140 month; mean 69 month follow-up) with respect to clinical examination results, KT-1000 arthrometer measurements, muscle strength, Tegner activity score, Lysholm score, patient satisfaction, sports performance level, graft retear, contralateral ACL tear, and additional meniscus surgery. The double-bundle approach was found to be favourable to single-bundle based on the Lachman test, pivot-shift test, KT measurements, and Tegner score. There were no significant differences between groups in range of motion, muscle strength, Lysholm score, patient satisfaction, postoperative sports activity level, graft retear, or secondary meniscal tear between the two groups.