Background: Older adults often use multiple medicines to manage comorbidities well or to prevent associated complications. This study aims to determine polypharmacy, the use of potentially inappropriate medications (PIMs) using the 2019 Beers Criteria and to determine the Medication Regimen Complexity Index (MRCI) score. It also aims to identify factors associated with the presence of PIMs and the MRCI score. Methods: This cross-sectional study was carried out between 6 and 2023 and 5 May 2023 in a community pharmacy in Turkey. Elderly patients over 65 years of age, who used at least one drug, and who came to the pharmacy for any reason were included in the study. PIMs were determined according to the 2019 Beers Criteria. The Turkish validated version of the MRCI was used to determine the medication complexity score. Results: 200 patients were included in this study. 59.5% of the patients were female and the median age was 70 (IQR, 66-74.75). Polypharmacy was detected in 33% of patients. The use of PIMs was determined in 63.5% of the patients. The median of the MRCI score was 11 (IQR, 7–15). The number of chronic diseases and drugs, presence of polypharmacy, MRCI score and mental disorders were found to be significantly higher in those with PIMs than in those without (p < 0.05). Having less than eight years of education, presence of polypharmacy, the presence of comorbidity (diabetes mellitus, cardiovascular disease, thyroid, chronic obstructive pulmonary disease (COPD), asthma and mental disorders) were associated with significantly higher MRCI scores (p < 0.05). Conclusions: According to the results of our study, it was found that the elderly patients who came to the pharmacy had low MRCI scores, but had high PIMs use. Community pharmacists have an important role in identifying inappropriate drug use, so they should be trained to develop skills in identifying and reducing PIMs in older patients.