AIM Polypharmacy and potentially inappropriate medications (PIMs) are prominent prescribing issues in elderly patients. The purpose of the study was to investigate the prevalence of PIMs identified by the Beers 2015 and 2012 criteria in older patients in China and identify the correlates of PIMs. METHODS This retrospective, cross-sectional study was conducted at Peking University First Hospital. The Beers 2015 and 2012 criteria were applied to evaluate PIMs among hospitalized patients. The associations between PIM use and independent variables were analyzed by logistic regression. The differences between PIM use according to Beers 2012 and 2015 criteria were calculated using chi-squared and kappa tests. RESULTS A total of 456 patients were analyzed; 244 (53.5%) and 204 (44.7%) patients had at least one PIM identified by the Beers 2015 and 2012 criteria, respectively. The most frequent PIMs were proton-pump inhibitors (PPIs), benzodiazepines, and benzodiazepine receptor agonists according to the Beers 2015 criteria. PIMs identified by the Beers 2015 criteria were associated with excessive polypharmacy (OR 1.864, 95% CI 1.210-2.871), a Barthel index ≤60 (OR 1.935, 95% CI 1.056-3.546), and the length of stay (OR 1.066, 95% CI 1.037-1.097). PIM use increased significantly between two criteria (chi-squared test, P<0.001), but good accordance was found between the previous and updated criteria (kappa test 0.782, P<0.001). CONCLUSION Our study showed a high prevalence of PIM use in China, which was associated with various correlates. The Beers 2015 criteria detected significantly more PIMs than the 2012 criteria due to the inclusion of PPIs.