Introduction: This study was conducted to examine the knowledge levels and practices of older individuals about rational drug use. Materials and Method: This descriptive study was conducted on 382 older individuals. The data were collected with the Rational Drug Use Survey through face-to-face interview method. The data were evaluated through the chi-square test and descriptive analysis methods. Results: In the study, 72.5 % of the older individuals stated that they used drugs without a prescription of a doctor, 23.6 % stated that they increased/decreased their doses without consulting the doctor, 91.1 % stated that they complied with the drug hours recommended by the doctors, and 44.2 % stated that they quit medication before the date prescribed by the doctor. Conclusion: The most important problems of older individuals concerning the rational drug use were determined to be using drugs without the prescription of a doctor and quitting the medication before the date recommended by the doctor. In line with these results, informing and supporting older individuals about rational drug use will make significant contribution for the rational drug use.