BackgroundDelirium is a common acute mental disorder, and its adverse outcomes often cause distress to both patients and their families. Despite its prevalence in patients treated in emergency departments, delirium is frequently overlooked.AimThis study aims to systematically evaluated and meta‐analysis the prevalence of delirium among emergency patients, providing insights into its prevalence and offering guidance for its management and prevention.Study DesignObservational studies on the prevalence of delirium in emergency departments were systematically searched in PubMed, Embase, the Cochrane Library and Medline databases. Relevant English‐language studies published up to 18 September 2023 were reviewed, and meta‐analysis was conducted using Stata 14.0 software. Quality assessment of included literature was performed using the methodological index for non‐randomized studies (MINORS), and publication bias was assessed using Egger's test.ResultsThirteen studies encompassing a total sample size of 33 839 cases were included, with 3082 cases of delirium incidents. The findings revealed a 15% prevalence rate of delirium in emergency departments, with a 95% confidence interval (CI) of (0.10, 0.20) and an overall heterogeneity of 98.37% (p = .000). Among emergency department patients over 65 years of age, the prevalence of delirium was 12%, with a 95% CI of (0.07, 0.19) and a heterogeneity of 94.59%. For patients over 18 years of age, the prevalence was 17%, with a 95% CI of (0.10, 0.25) and a heterogeneity of 98.94%.ConclusionsThis meta‐analysis reveals an overall 15% prevalence rate of delirium among patients in emergency departments.Relevance to Clinical PracticeIn clinical practice, emergency medical staff should strengthen the screening and management of emergency delirium patients.