Objective: To examine associations between potentially inappropriate medication, use and the risk of falls, unplanned hospitalization and death in older patients receiving initial care in a geriatric day hospital due to acute conditions. Methods: Cohort study with older adults referred to a geriatric day hospital from 2014 to 2017 due to acute conditions. Patients were submitted to comprehensive geriatric assessment. Use of medications was analyzed according to Beers Criteria 2019. Outcome assessment was based on monthly follow-up telephone calls made over the course of one year. Results: In this sample, 40.6% of patients had been prescribed at least one potentially inappropriate medication, particularly proton pump inhibitors (66.5%). Over the course of follow-up, 44.7% of patients receiving potentially inappropriate medications sustained at least one fall (p=0.0043) and 70% visited the emergency department (p=0.0452). These outcomes were more common among patients using two or more of drugs. Use of potentially inappropriate medication was associated with a 64% increase in the odds of unplanned hospitalization and a two-fold increase in risk of death. Conclusion: Associations between potentially inappropriate medication use and unfavorable outcomes such as falls and unplanned hospitalizations within one year of admission to a geriatric day hospital support the application of Beers Criteria and emphasize the importance of periodic prescription review, deprescription and rational use of these drugs whenever possible.