Objective: Atrial fibrillation (AF) is one of the most common arrhythmic disorders worldwide. This study aims to describe the prevalence of AF in various cities in Indonesia using single-lead hand held electrocardiography linked to a smartphone-based application. Methods: This is a cross-sectional epidemiological study conducted at tertiary hospital of major cities in Indonesia, between January 2018 and July 2019. The AliveCor Kardia™ Mobile system device was used as a screening tool for AF and confirmed its finding with clinical diagnoses made by cardiologists. Results: A total of 9773 subjects were enrolled in this study. The prevalence of AF reported by the device and cardiologist was 3.2% and 3.5%, respectively. AF prevalences are equal in men than women. The majority of subjects (56%) are having low risk for stroke or systemic thromboembolism. Prevalence of risk factors such as heart failure, hypertension, diabetes, and history of stroke among AF patients were 50%, 22.9%, 31.9%, 13.5%, and 5.8%, respectively. Conclusion: The prevalence of AF at referral hospitals visitors based on smartphone diagnosis in Indonesia is 3.2%. © 2024 The Author(s). Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.