Background: Elderly patients generally have more than one disease, so they need several drugs to treat the condition and Potentially Inappropriate Medication (PIM). Objective: This study aimed to examine the inaccuracy of prescription drugs in the elderly using Beer's criteria 2019. Methods: The research method used an observational study with a descriptive cross-sectional design. Beer's Criteria 2019 was compiled by The American Geriatrics Society (AGS) and grouped PIM into five categories. A total of 138 prescriptions met the inclusion criteria at the Internal Medicine Clinic. Results: The results showed that the elderly who received the prescription was in the age range of 60-69 years (73.2%), male gender (54%), and had comorbidity (77.5%). Of the 138 prescriptions for elderly patients, 117 prescriptions for elderly patients experienced PIM incidence (84.78%). The percentage of PIM incidents was based on categories; namely, category 1 was 74.2%, category 2 was 3.5%, 3 was 16.7%, category 4 was 3%, and category 5 was 2.5%. Medicines that include PIM in category 1 are lansoprazole, glimepiride, glibenclamide, alprazolam, diazepam, amitriptyline, diclofenac sodium, ibuprofen, meloxicam. PIM in category 2 are cilostazol, pioglitazone, and diclofenac sodium. Category 3 PIMs include furosemide, spironolactone, and hydrochlorothiazide (HCT), category 4 PIMs include dexamethasone-sodium diclofenac, methylprednisolone-ibuprofen, and alprazolam-codeine, and category 5 PIMs include spironolactone, ciprofloxacin, and ranitidine.. Conclusion: This study concludes that the elderly are at risk for receiving inappropriate drug prescriptions. Patients received more drugs belonging to category 1 PIM than category 2, 3, 4, and 5.