We assessed the hypothesis that having a non-English-speaking background (NESB), being very elderly, living alone, and having cognitive impairment were contributing factors to anticoagulant under-utilisation for atrial fibrillation in our local community. A questionnaire was mailed to 532 general practitioners (GPs) in three areas of metropolitan Sydney, Australia. The questionnaire included five case scenarios, regarding either an English-speaking background (ESB) patient, or an NESB patient, each characterised by potential barrier(s) for anticoagulant usage: being (1) elderly; (2) elderly with mild dementia; (3) elderly with mild dementia and living alone; (4) elderly with severe dementia; and (5) very elderly. The overall response rate was 34%. The percentage of GPs recommending anticoagulation was 57%, 50%, 6%, 25% and 23%, respectively, for the ESB scenario, and 48%, 32%, 4%, 14% and 18%, respectively, for the NESB scenario. Eighty-eight percent of GPs rated 'adherence to International Normalized Ration monitoring' as 'very important' in their decision. In conclusion, the factors proposed in our hypothesis were associated with a lower likelihood for anticoagulant prescription for atrial fibrillation.