Oral anticoagulant therapy has been shown to be of benefit also in elderly patients in various therapeutic and prophylactic indications. Despite strong evidence in literature, doctors still refuse to prescribe oral anticoagulants to geriatric patients in daily routine. Main reason for this decision is the fear of secondary bleeding complications. According to clinical trial data, distinct risk factors for bleeding attributed to anticoagulant treatment may be determined: age >70 years, female gender, recurrent bleeding events, alcohol/drug abuse, diabetes, anaemia and polypharmacy. The entire article reveals the literature in Medline and Cochrane Library from 1980 to 2009 including the hits "polypharmacy - anticoagulant treatment - elderly patients". It further highlights risk assessment strategies in elderly patients, and possible pharmacokinetic and -dynamic interactions of drugs co-administered with oral anticoagulants.