Abstract Older adults' use of over-the-counter (OTC) medications is usually a self-initiated behavior that may have important health consequences. A sample of 186 adults age 65 years and over was interviewed to describe their use of 16 OTC substances and their management of the most commonly used OTC medications. Subjects reported using almost twice as many OTC as prescription medications. A structured interview format elicited subjects' self-reports of decisions, judgments, and actions used to manage aspirins, laxatives, antacids, and vitamins. Most reported using the specific OTC preparations often. Health care providers were common but not exclusive sources of information about these products; few subjects acknowledged being influenced by advertisements. Although subjects' reported dosages and scheduling of agents were judged appropriate by nurses, some overuse of laxatives was noted, together with some continuation of laxative and antacid administration for excessive lengths of time for persisting symptoms. Few subjects identified precautions associated with the OTC medications. Questions were raised about older adults' perceptions regarding vitamin use for particular symptoms. The results of the study indicate the need for educational programs for older adults and further research about OTC substance use among these individuals.