Patient controlled analgesia (PCA) offers meaningful advantages over traditional analgesia. However, PCA medical errors with PCA can be dangerous and even fatal. Errors associated with patient controlled analgesia (PCA) therapy are described as are ways to minimize such errors. This report is based on data from the United States Pharmacopeia (USP) and Institute for Safe Medication practices (ISMP) Medication Errors Reporting Program. PCA by proxy, appropriate patients selection for PCA, patient monitoring, patient education, medication mix ups and practice related errors are discussed. Staff training is addressed. Methods to minimize errors associated with pump purchasing, PCA prescribing, initiation, and monitoring are described. Recommendations for pharmaceutical manufacturers elated to PCA therapy are provided. (C) 2005 by The Haworth Press, Inc. All rights reserved.