The use of medications is common in elderly persons, and this population has the highest risk of medication-related problems. Elderly persons are more susceptible to the effects of various medications for a number of reasons. It is well known that polypharmacy is one of the most serious problems in caring for elderly persons; however, many of these patients continue to receive medications that have an increased risk of causing harm. In 1991, an important article was published about inappropriate medication use in the elderly population. This article raised awareness of the problem and presented explicit criteria for determining which medications were inappropriate for elderly patients residing in long-term care facilities. This list of drugs is still used for evaluating medications taken by elderly persons and for determining whether satisfactory prescribing practices are being used. We reviewed the medications described as inappropriate for elderly persons and searched the scientific literature to determine whether evidence exists to defend or refute the labeling of particular drugs. At times, evidence was difficult to find, and many of the original studies were dated. For most medications listed as inappropriate, we found evidence to support these designations.