AbstractBackground and aimDelirium has been presented as the leading cause of sudden change in the mental state of patients with coronavirus disease 2019 (COVID‐19). Given that the delayed diagnosis of such a dysfunction is often associated with excess mortality, it seems essential to devote vastly more attention to this significant clinical characteristic.Materials and methodsThis cross‐sectional study was performed on 309 patients [viz. 259 cases hospitalized in general wards and 50 individuals admitted to the intensive care unit (ICU)]. For this purpose, a Demographic‐Clinical Information Questionnaire, the Confusion Assessment Method (CAM), the Confusion Assessment Method for the ICU (CAM‐ICU), the Richmond Agitation‐Sedation Scale (RASS) and face‐to‐face interviews were completed by a trained senior psychiatry resident. The data analysis was further done with the SPSS Statistics V22.0 software package.ResultsOut of 259 patients admitted to the general wards and 50 cases in the ICU due to COVID‐19, 41 (15.8%) and 11 (22%) individuals were diagnosed with delirium, respectively. As well, a significant relationship was observed between the incidence rate of delirium and age (p< 0.001), level of education (p< 0.001), hypertension (HTN) (p= 0.029), a history of stroke (p= 0.025), a history of ischemic heart disease (IHD) (p= 0.007), a history of psychiatric disorders, a history of cognitive impairment (p< 0.001), use of hypnotic and antipsychotic medications (p< 0.001) and a history of substance abuse (p= 0.023). Among 52 patients with delirium, only 20 cases had received psychiatric consultation by consultation‐liaison psychiatry service for the possibility of delirium.ConclusionIn view of the high frequency of delirium among COVID‐19 inpatients, their screening for this important mental state should be a priority in clinical settings.