PURPOSE: The study is for the evaluation of the role and importance of the T1- weighed axial image on the MR diagnosis of the anterior cruciate ligament(ACL) tear. MATERIALS AND METHODS: We reviewed the axial findings of injured ACL on MR images of arthroscopically confirmed 41 patients. The points of ^CL abnormality on axial image were centered on the substance signal change, thickness change, focal bulge or irregularity of medial border. RESULTS: ACL complete tears were present in 31 patients and partial tears in 5 patients and, ligamentous atrophy or loss by chronic tear in 5 patients. Completely torn ACL were seen as diffuse swelling with abnormal substance signal(A) in 24 cases, focal bulge or irregularity of medial border(B) in 6 cases, normaIcy in 1 case. 9 cases among type A cases also showed type B features. Partially torn ACL were seen as roedial marginal irregularity in 3 cases, mild and diffuse swelling in 1 case, normaIcy in 1 cases. Atrophied or absent ACL fibers by chronic tears in 5 cases were demonstrated on axial images as abnormally thin fibers or so-called "empty lateral wall". Detection rate for ACL abnormality suggestive of fear on Tl-weighted axial image very high(94%, 39/41 ). CONCLUSION: Because Tl-weighted axial image serves as another good reference of plane for direct visualization of injured ACL with high abnormality detection rate, it would aid in the diagnosis of ACL tear.