Background: Oral anticoagulation (OAC) is the most effective treatment to prevent strokes in patients with atrial fibrillation (AF). Many older patients are not prescribed OAC. Objective: To explore which co-morbid conditions in older patients with AF have been associated with under-treatment with OAC, or were used as exclusion criteria for trials, or have been associated with increased risk of bleeding. Methods: A Pubmed search was conducted with the terms elderly, atrial fibrillation, stroke risk, bleeding risk, intracranial haemorrhage, cognition, fall risk, renal dysfunction, alcohol abuse, malignancy, polypharmacy, NSAID, under-treatment, under-use and under-prescription. Results: Higher age is associated with under-treatment. Patients with a higher risk of stroke show higher rates of bleeding complications. The associations of bleeding rates with possible contraindications are inconsistent. Discussion: Published bleeding rates reflect selection bias, describing mainly relatively healthy older patients. The use of stratification schemes for stroke risk and for bleeding risk will have to be implemented. Conclusion: The decision to prescribe OAC in older patients with AF remains a challenging task since bleeding risk is difficult to estimate reliably. Stratification schemes may be helpful.