A case is reported in which metoclopramide, midazolam, propofol, and pethidine were injected arterially during the course of anaesthesia, resulting in oedema and discolouration of the hand initially, but no long-term sequelae. An AVI 470 pump (3M Corporation) was used to control the infusion, and prevented backflow through a cannula which was unintentionally sited in an artery rather than a vein. Few anaesthetic drugs have their effects well documented when given arterially, and in particular, there were no previous reported cases involving metoclopramide in this context. The pharmacology of metoclopramide is discussed with reference to the drug's known effects on vascular beds and platelet function.