INTRODUCTION Multimorbidity in older adults leads to polypharmacy with all its hazardous outcomes and drug‑related problems. OBJECTIVES We aimed to assess the difference in the number of drugs between admission to and discharge from a geriatric ward and identified the patient‑related factors associated with changes in the drug regimen. PATIENTS AND METHODS This retrospective cross‑sectional study included 301 geriatric patients who underwent drug optimization in line with the Beers and STOPP/START criteria. The numbers of drugs per individual at hospital admission and discharge were compared using the Wilcoxon signed‑rank test. A multiple linear regression model was used to identify patient characteristics that influenced the observed difference in the number of drugs following geriatric hospitalization. RESULTS A significant reduction of 1.29 in the number of drugs per patient, on average, was observed. The Spearman's correlation coefficient between the number of prescribed medications and the number of coexisting conditions per individual changed from 0.28 to 0.51. The patient‑related characteristics that jointly and independently explained (P <0.001) the difference in the number of drugs in the multiple regression model (R2 = 0.73) were the number of drugs on admission, number of coexisting conditions, age, fact of living alone, and the incidence of adverse drug reactions. CONCLUSIONS Geriatric hospitalization results in deprescribing rather than prescribing medications, especially in individuals who were overtreated, older, undernourished, at risk of an adverse drug reaction, and living alone. Appropriate deprescribing may potentially lead to fewer drug‑related problems in the senior population as well as reduce health care costs.