BACKGROUND: The relationship between the signal/noise quotient value and knee function scores has not been extensively studied. Thus, we aimed to investigate the correlation between graft maturity and knee function after anterior cruciate ligament reconstruction.METHODS: In this retrospective study, we included patients (n=50; 28 male patients; age, 31.0 years) who underwent anterior cruciate ligament reconstruction with autogenous tendons between August 2016 and August 2018. At 6 months and 2 years postoperatively, the signal/noise quotient values of the tibia and femur, indicating graft maturity, were measured using magnetic resonance imaging. The Tegner, Lysholm, and International Knee Documentation Committee scores were used to evaluate knee function. Mean signal/noise quotient values of the grafts’ femoral and tibial ends were considered the final signal/noise quotient values. The correlation between the signal/noise quotient value at 6 months postoperatively and knee function score at 2 years postoperatively was analyzed. RESULTS: All patients were followed up for 24–28 months. The International Knee Documentation Committee, Lysholm, and Tegner scores of the knee joint at 6 months and 2 years postoperatively were significantly higher than the preoperative scores, and those at 2 years postoperatively were significantly higher than those at 6 months postoperatively. The signal/noise quotient value for all patients at 6 months postoperatively was negatively correlated with the Lysholm, International Knee Documentation Committee, and Tegner scores at 2 years postoperatively.CONCLUSION: The signal/noise quotient value based on magnetic resonance imaging in the early stage after anterior cruciate ligament reconstruction can predict knee function in the later stage.