Despite increased adoption of computerized provider order entry, medication errors are a continued problem in acute care settings, particularly in high-risk ones such as intensive care units. These concerns are perhaps greatest for patients with acute clinical deterioration who need rapid resuscitative efforts. This study evaluated medication errors during activation of medical emergency teams. While the study was performed at a single site with a limited sample size, the findings of nearly 1 in 2 doses administered in error was alarming. More than 65% of errors involved breaks in aseptic technique, while nearly half of those remaining were prescribing errors. Almost 15% of errors were classified as at least moderate in severity, underscoring the need for greater attention to medication safety in these clinical situations.