Ethanol sclerotherapy is a first line management therapy for low flow vascular malformations. It is usually performed under general anesthesia because of the pain associated with ethanol injection. Ethanol sclerotherapy frequently produces minor local complications but may rarely produce catastrophic cardiopulmonary complications. This report describes the cardiovascular collapse associated with an ethanol sclerotherapy procedure in an 11-year- old child. The evidence for ethanol-induced cardiovascular derangements is discussed.