Three patients were studied with a 0.3% superconducting magnet to assess the role of magnetic resonance (MR) imaging in the recognition and evaluation of diastematomyelia and associated abnormalities. Comparison was made with other imaging techniques, including metrizamide computed tomographic (CT) myelography. With MR imaging, the divided spinal cord was well imaged in its entire craniocaudal extent, comparable to CT myelography. The body septum, when it contained a marrow cavity, was seen well. In 2 patients, dural ectasia and low position of the spinal cord with and without associated lipoma were clearly imaged. MR imaging demonstrated associated syringohydromyelia in 1 patient that was not detected by other radiologic studies. Once the bony details of the abnormality are defined, MR imaging can delineate the presence and extent of the divided spinal cord as well as its associated abnormalities adequately, obviating other studies.