When patients are admitted to the intensive care unit, medication histories can be obtained from alternate sources. In this study, admission medication histories were obtained from family members or outpatient pharmacies, then compared with the history given by the patient once their delirium resolved or they were extubated. The most common type of discrepancy from both alternate sources was addition, followed by omission. Histories obtained from families had slightly fewer discrepancies, and most discrepancies were of low risk of harm.