Using polytomographic techniques, gas myelography was performed in 162 patients with post-traumatic neurologic deficit. The type, extent, and location of lesions were easily demonstrated, allowing adequate preoperative surgical planning. In cases in which expected neurologic improvement did not follow surgery, postoperative myelography provided information so that remedial measures could be taken. No neurologic deterioration was noted in any of the patients and furthermore, arachnoiditis, which may accompany positive contrast myelography, has not been detected in any of the patients in the series reported.