BACKGROUND/AIMS: This study aimed to compare the muscle strength and thickness of individuals who underwent anterior cruciate ligament (ACL) reconstruction using a hamstring tendon graft for at least 12 months with uninvolved limbs and healthy controls. MATERIALS and METHODS: This study included 25 individuals who underwent ACL reconstruction [age: 29.56±8.25 years; Body Mass Index (BMI): 27.27±3.89 kg/cm2] and 25 healthy participants (age: 27.12±5.94 years; BMI: 24.70±3.03 kg/cm2). Muscle thicknesses of the vastus medialis oblique (VMO), rectus femoris (RF), biceps femoris (BF), and semitendinosus-semimembranosus (SS) muscles were evaluated by ultrasonographic measurement. Muscle strength measurements using an isokinetic system were performed. RESULTS: VMO (p<0.001) and RF (p<0.001) muscle thickness were higher in the uninvolved limb than in the surgical limb. The concentric quadriceps muscle (p=0.029), eccentric quadriceps muscle (p=0.012), and eccentric hamstring muscle strengths (p=0.001) were significantly higher in uninvolved limb, which was similar concentric hamstring muscle strength (p>0.05). Muscle thickness and muscle strength of the control group and the surgical limbs were similar (p>0.05). CONCLUSION: An average of 3 years has passed since the operation; however, VMO and RF muscle atrophy and decreased hamstring and quadriceps muscle strength continued. These results revealed that the use of the limb, which has not fully achieved its functionality, is limited, and individuals try to compensate for this situation by the uninvolved limb.