A postlaminectomy pseudomeningocele is a spherical, fluid-filled space with fibrous capsule lying dorsal to the thecal canal in the laminectomy opening that occasionally develops after surgery. Eight cases were found in 400 symptomatic postlaminectomy patients undergoing computed tomographic examination. The contents are of cerebrospinal fluid density and may or may not have demonstrable communication with the subarachnoid space. Whether they are the cause of symptoms is conjectural; none of these eight patients had surgical removal.