Objective: Atrial fibrillation (AF) is the most important risk factor for ischemic stroke. Anticoagulation therapy can substantially decrease the risk of stroke in patients with AF. The aim of our study was to investigate the patient’s comorbidities and management of patients with AF on the discharge. Methods: From 5382 consecutive patients admitted in our institution between January 2005 and March 2008, 525 (mean age 66.4±11.4 years, 53.3% male) had AF upon discharge, who were included in this retrospective study. Patients were divided in two groups according to prescription of anticoagulation therapy at discharge. Continuous data were compared between groups using a two-tailed unpaired Student t test. Discrete variables were compared using Chi-square test or Fisher’s exact probability test as appropriate. Logistic regression analysis was used to identify the independent clinical and echocardiographic predictors of prescribing oral anticoagulation therapy. Results: Associated comorbidities of AF in our patients were: ischemic heart disease (21.4%), hypertensive heart disease (27.44%), valvular heart disease (17.4%), congestive heart failure (47%), chronic obstructive pulmonary disease (6.7%), and diabetes 14.3%). Of 525 patients 76% were discharged on beta-blockers, 67% on angiotensin converting enzyme inhibitors, 23% on digoxin, 16% on calcium antagonists, 67% on diuretics, 72% on aspirin, and 27% on oral anticoagulant (OAC) therapy, 11% were with both antithrombotics. Multivariate analysis showed that the under-prescription of OAC therapy in patients with AF was independently associated with elder age (OR=0.916, 95%CI 0.891-0.942, p<0.001), non-enlarged left atrium (OR=1.148, 95%CI 1.100-1.198, p<0.001) and good left ventricular ejection fraction (OR=0.970, 95%CI 0.948-0.993, p=0.011). Conclusions: Patients with atrial fibrillation were mainly with ischemic, hypertensive heart disease and congestive heart failure. Our study, suggests underuse of anticoagulation therapy. The independent predictors of under prescription of anticoagulants in patients with atrial fibrillation were elder age, non-enlarged left atrium, and good left ventricular ejection fraction. Medical treatment with other groups of drugs for atrial fibrillation and comorbidities seems to be according to current guidelines.