[en] We reviewed MR images of 50 patients with spondylolisthesis to disclose MR findings of spondylolysis. In almost half of our series, spondylolysis was detected as a low signal intensity band traversing in the pairs interarticularis on both T1 and T2 weighted images. Sagittal images was superior to axial image in detection of the low signal intensity band. In some patients, a focal high signal intensity accompanying the low signal intensity band was considered to be fluid collection within pseudoarthrosis due to spondylolysis on T2-weighted image. (author)