Background: Insomnia is a frequent problem in acutely hospitalized older adults, particularly in those suffering from polymorbidity and treated by polypharmacy. The aim of our study was to describe the prevalence of insomna and patterns of inappropriately prescribed hypnosedatives in acutely hospitalized older patients in the Czech Republic. Study aims: 438 patients (≥65 yrs) acutely hospitalized at 3 geriatric clinics (Brno, Hradec Králové, Praha) in the Czech Republic underwent a comprehensive geriatric assessment (CGA) using the EUROAGEISM H2020 assessment protocols. Descriptive statistics was used to determine the prevalence of insomnia and use of hypnosedatives. Explicit criteria of potentially inappropriate medications (PIMs), mainly 2019 Beers criteria and 2015 EU(7)-PIM list were applied to determine inappropriate patterns of hypnosedatives use. Methods: There were included 438 patients (≥65 years) in 3 geriatric medical acute centers in Czech Republic. All patients underwent a complex geriatric examination (CGA). Rationality of prescription of sedative-hypnotic medication was analysed according to explicit criteria of potentially inappropriate medication use in geriatrics (revised 2019 Beers criteria and EU(7)-PIM list). Results: 16.9% (N=74) seniors had diagnosed insomnia in their medical records, but 34,6% used hypnosedatives in the evening or at night (e/n). 13.8% reported e/n use of drugs aggravating insomnias (particularly beta-blockers- 6.4%, diuretics-2.5% and theophylline- 2.1%). Most frequent hypnosedatives used were: antipsychotics e/n (18.5%), Z-drugs (16,2%) and benzodiazepines e/n (BZD, 14,2%). Non-geriatric doses were determined in users of Z-drugs (10.5%) and sedative antidepressants e/n (1,8%), longer than recommended geriatric duration of therapy has been described for Z-drugs (5.9 %,>1month), BZDs e/n (5,3%,>1month) and sedative antidepressants e/n (3,3 %, >6 months). In total, 1PIM was prescribed to 7.5% of seniors (N=33), 2PIMs to 2.5% and 3PIMs to 1,1% of seniors. Combination of hypnotics and other sedative drugs was documented in 5.9% of cases. Conclusions: Inappropriate patterns of hypnosedative use in acutely hospitalized seniors in the Czech Republic at geriatric clinics were found particularly in excessive indication of antipsychotics e/n, inappropriate dosing of Z-drugs and long-term use of BZDs e/n. Grants: InoMed project (reg. No: CZ.02.1.01/0.0/0.0/18_069/0010046, 2019-2022), EUROAGEISM H2020-MCSF-ITN-764632 project, PROGRESS Q42 Faculty of Pharmacy, Charles University, SVV 260417