Anterior cruciate ligament (ACL) injuries are associated with a persistent decrease in quadriceps muscle strength despite rehabilitation. Previous studies have shown that ACL injury results in muscle disorganization, which could account for the loss in strength. We sought to use dual-spin echo and multi-spin echo sequences to estimate T2 of the vastus lateralis in injured and uninjured limbs of twenty-two ACL injured subjects. T2 of the injured limb was significantly longer than the uninjured limb for both pulse sequences. Our results suggest that T2 relaxation may provide clinicians a means to quantitatively monitor muscle recovery after ACL injury.