BACKGROUND: There are established differences in cardiovascular disease in different racial groups. Worldwide, the literature regarding the clinical epidemiology of atrial fibrillation in non-white populations is scarce. OBJECTIVES: To document the prevalence of atrial fibrillation (AF) in the multiracial population of Malaysia, and to describe the clinical features and management of these patients. SETTING: Busy city centre general hospital in Kuala Lumpur, Malaysia, over a 1-month period. SUBJECTS: One-thousand four hundred and thirty-five acute medical admissions, of whom 40 patients (2.8%) had AF. RESULTS: Of 1435 acute medical admissions to Kuala Lumpur General Hospital over the 4-week study period, 40 had AF (21 male, 19 female; mean age 65 years). Of these, 18 were Malay, 16 Chinese and six Indian. Nineteen patients had previously known AF (seven with paroxysmal AF) and 21 were newly diagnosed cases. The principal associated medical conditions were ischaemic heart disease (42.5%), hypertension (40%) and heart failure (40%). Dyspnoea was the commonest presentation, whilst stroke was the cause of presentation in only two patients. Investigations were under-utilised, with chest X-ray and echocardiography in only 62.5% of patients and thyroid function checked in 15%. Only 16% of those with previously diagnosed AF were on warfarin, with a further three on aspirin. Anticoagulant therapy was started in 13.5% of patients previously not on warfarin, and aspirin in 8%. Records of contraindications to warfarin were unreliable, being identified in only 25%. For those with known AF, 58% were on digoxin. For new onset AF, digoxin was again the most common rate-limiting treatment, initiated in 38%, whilst five patients with new onset AF were commenced on amiodarone. DC cardioversion was not used in any of the patients with new onset AF. CONCLUSION: Amongst acute medical admissions to a single centre in Malaysia the prevalence of AF was 2.8%. Consistent with previous similar surveys in mainly western (caucasian) populations, standard investigations in this Malaysian cohort were also inadequate and there was underuse of anticoagulation, medication for ventricular rate control and cardioversion to sinus rhythm.