Polypharmacy is an important public health problem affecting the elderly. In fact, although it is sometimes necessary to use several drugs to control their pathologies, unnecessary or inappropriate medication is often prescribed, and this population is more susceptible to adverse effects and pharmacological interactions. Thus, polymedication is an important cause of morbidity and mortality in this age group. However, it is a difficult problem to deal with, due to the existence of multiple contributing factors, among which are medical specialisation, which leads to multiple prescribers for the same patient, the need to use multiple drugs for the same disease and communication failures. Nevertheless, several strategies have been developed to detect and minimise this problem, such as the drug regimen review and the Beers and STOPP/START criteria, which have been shown to be effective in improving the appropriateness of prescribing in the elderly. Thus, this book reviews the most current literature on polymedication in the elderly as well as ways to address and prevent it.