Error in medication prescribing is a well-described problem in the hospital setting. This study sought to further characterize prescribing errors by determining the incidence of one specific type of error—errors in the route of administration. These errors were common, most frequently involving prescribing for the wrong route (eg, orally instead of intravenously), and cardiovascular drugs were most often implicated. The author provides suggestions for means of preventing these errors. A prior study by Lesar was one of the first to characterize the incidence of medication error in a teaching hospital setting, and he discusses the implications of error in the route of administration in a WebM&M commentary.