Serum uric acid (SUA) is a simple and independent marker of morbidity and mortality in a variety of cardiovascular diseases. In this study we aimed to examine the relationship between serum uric acid levels and clinical, biological and echocardiographic characterstics in patients with non-valvular atrial fibrillation (AF). One hundred and seventy patients with non-valvular atrial fibrillation were included (mean age: 66.3 ± 8.5 years; 37% male patients). Hyperuricemia was defined as SUA ≥ 360 μmol/L in women and ≥ 446 μmol/L in men determined determined according to receiver operating characteristic curve. Clinical, biological and echocardiographic characterestics were compared in patients with ( n = 51) and without hyperuricemia ( n = 119). In AF patients, those with hyperuricemia had the most adverse biological risk profile including the highest rates of renal dysfunction ( P < 0.001) and the highest mean level of fibrinogen ( P = 0.033), c-reactive protein ( P = 0.05), calcemia ( P = 0.016) and leucocytosis ( P = 0.03). Patients with hyperuricemia showed also more enlarged left atrium ( P = 0.039) and lower left ventricle ejection fraction ( P = 0.01) and peak myocardial systolic velocity measured at the mitral annulus (Sa) in tissue Doppler imaging (TDI) ( P = 0.01) High serum uric acid levels were associated with a low left ventricle contractile function, enlargement of left atrium, inflammatory biological profile and could provide additional prognostic information on future thromboembolic events in patients with AF.