A case of pontine haemorrhage following lumbar myelography using iohexol is described. Stress, inducing transient hypertension during the procedure, with superimposed neurotoxicity from contrast medium (iohexol) is suggested as a possible mechanism. No brain stem lesion was seen on the initial brain CT scan, possibly because of the high attenuation of the contrast medium in the subarachnoid space. A delayed CT brain scan demonstrated the pontine haemorrhage and was necessary to confirm the diagnosis.