Background: Elderly patients are at an increased risk of developing complications from taking medication. Little is known about the inappropriate use of medication in elderly patients presenting to the emergency room, especially in very old patients. Methods: A random sample was drawn from patients aged 60 years or older who had been discharged from a medical emergency room. Charts were analyzed retrospectively. Potentially inappropriate medication was defined according to the 1997 Beers criteria. Results: At presentation, 24 (12.3%) of 195 patients aged 60 years and older were taking potentially inappropriate medications. Of 65 patients aged 80 years or older, 27.7% presented with potentially inappropriate medication, as compared to 4.6% in 130 patients aged 60-79 years. Patients older than 80 years were six times more likely than those aged 60-79 years to take problematic medication, despite similar average numbers of medications per patient. Emergency department physicians added potentially inappropriate drugs in three cases (1.5%). Conclusions: Among elderly patients presenting to the emergency department, one in 10 takes at least one problematic drug. Very old patients are at the greatest risk. Presentation of elderly patients to the emergency department offers an opportunity to review and optimize drug prescriptions.