1. Clinical and laboratory data presented suggest that pantopaque and other iodized oils may contribute to, or possibly cause, severe reaction within the subarachnoid space.
2. Verbal communication indicating similar experience among orthopaedists and neurosurgeons has suggested to us that there is need for a more critical evaluation of the properties of pantopaque and other iodized oils and a more conservative approach to their use than is often practised. The importance of complete removal of the substance is evident.