Six hundred and eighteen patients aged 14–25 years with ACL-deficient knees were randomized to receive either hamstring tendon ACL reconstruction alone (n=312) or with an additional lateral extra-articular tenodesis (LET) (n=306). The primary outcome was graft rupture. Secondary outcomes included minor medical events, minor surgical events, contralateral ACL ruptures, overall reoperation rates, pain (P4), range of motion, and patient-reported outcomes (IKDC, KOOS, ACL-QOL). Outcomes were assessed up to 24 months. Overall, the results of the study revealed a significantly lower rate of graft rupture in the ACLR + LET group compared to ACLR alone, without an increase in overall adverse events or reoperation rates. These findings suggest that adding LET to ACLR in high-risk young patients significantly reduces the risk of graft failure without increasing serious complications.