Background: An estimated 30% of hospitalizations in the elderly may be drug-related. The Beers criteria are a list of potentially inappropriate medications (PIMs) generally considered unsafe in the elderly. These criteria are useful for assessing quality and safety of prescribing in the elderly population. Purpose: Evaluate PIM use, as defined by the Beers criteria, in elderly hospitalized patients. Methods: This cross-sectional study evaluated hospitalized patients ≥ 65 years old, consecutively admitted to general medical floors, starting 4/1/06 until 100 patients were enrolled. Each patient’s home, discharge, and inpatient medication profiles were screened for PIMs. Actual usage and duration of therapy, source of prescription, potential justification for use, and pharmacy interventions were also collected. Results: Based on home medication lists, 32% of patients were taking ≥ 1 PIM prior to admission; rising to 56% during hospitalization; and declining to 36% at discharge. Of the 93 active hospital PIM orders, 62% were new orders and 38% were continued from home; 85% were categorized as “high” risk; 8.6% were potentially justified; and pharmacists intervened on three of the PIM orders. Conclusion: The percentage of patients prescribed PIMs increased significantly during hospitalization, but returned to baseline at dismissal. Healthcare provider education regarding safe medication prescribing in elderly hospitalized patients, formulary changes, and alterations to preprinted orders may be needed.