101 patients scheduled for arthroscopic single-bundle anterior cruciate ligament (ACL) reconstruction were randomized to either a double-layer bone-patellar-tendon-bone allograft or a four-stranded hamstring tendon allograft. Patients were assessed for knee laxity via the Lachman test, KT-1000 arthrometer, and pivot-shift test, patient-reported functional scores, and the incidence of re-rupture over a minimum of a 3-year follow-up. At 3 years, significant differences in favour of the double-layer BPTB group were found for Lachman grading, the side-to-side difference in the KT-1000 arthrometer, Lysholm score, and IKDC subjective score. However, these differences were not of clinical significance.