Objective: Frailty is a complex age-related clinical disorder characterized by the decreased physiological capacity of multiple organ systems, leading to increased susceptibility to stressors. Because the clinical manifestations of frailty are heterogeneous, accurately diagnosing the degree of frailty and its predisposing factors is important. We investigated the prevalence of frailty and the related risk factors in elderly patients in emergency departments (EDs) in China using a clinical frailty scale (CFS) and a comprehensive geriatric assessment (CGA) tool.Methods: Elderly patients who were scheduled to be discharged from the acute ward of an ED within one week were recruited. They were asked to complete a set of surveys using CGA forms, comprising a CFS, a Nutritional Risk Screening 2002 form, laboratory tests for albumin level and body mass index, a Mini-Cog test for cognitive status, Barthel's activities of daily living index, an instrumental activities of daily living (IADL) assessment, a Geriatric Depression Scale-15 (GDS-15) assessment and a Cumulative Illness Rating Scale-Geriatric assessment.Results: Frailty prevalence in the recruited elderly patients was 33.33%. Frail elderly patients (CF≥5) also had more comorbidities, higher depression scores, and nutritional risks along with lower body mass indices, weight, quality-of-life scores and physical function scores. Cognitive impairment, depression, and education level were found to be the main impact factors on frailty.Conclusion: Frail elderly patients had greater cognitive problems and higher levels of depression besides physical dysfunction, which further aggravates frailty in older patients.