Elderly patients are at an increased risk of developing adverse drug events due to polypharmacy, co-morbidity and changes in physiology. Often, pharmacotherapy in frail elderly patients is initiated based on randomized trials from which this population has been excluded. In such cases, the question when to stop a medication may be as important as when to start it. It is important to consider whether the patient is using Potentially Inappropriate Medications (PIM) that should be stopped. Checklists can be helpful in detecting PIM. A recent study has shown that Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) criteria can identify clinically relevant PIM much better than the Beers criteria often used. These outcomes indicate that patient safety can be improved if clinicians use checklists such as the STOPP.