Aim Aortic stenosis increases left atrial (LA) pressure and may lead to its remodeling. This can cause supraventricular arrhythmia. The aim of this study was to determine if the size of the LA and the presence of atrial fibrillation are related to the prognosis of patients with aortic stenosis.Material and methods Clinical evaluation and standard transthoracic echocardiographic studies were performed in 397 patients with moderate to severe aortic stenosis.Results In all patients, LA dimension above the median (≥43 mm) was associated with a significantly higher risk of death [HR 1.79 (CL 1.06-3.03)] and a LA volume above the median of 80 ml was associated with a significantly higher risk of death [HR 2.44 (CI 1.12-5.33)]. The presence of atrial fibrillation was significantly associated with a higher risk of death (p <0.0001). The presence of atrial fibrillation [HR 1.69 (CI 1.02-2.86)], lower left ventricular ejection fraction [HR 1.23 (CI 1.04-1.45)], higher NYHA heart failure class [HR 4.15 (CI 1.40-13.20)] and renal failure [HR 2.10 (CI 1.31-3.56)] were independent risk factors of death in patients in aortic stenosis.Conclusion The size and volume of the LA and the occurrence of atrial fibrillation are important risk factors for death in patients with aortic stenosis. The presence of renal dysfunction, low left ventricular ejection fraction, high NYHA functional class and atrial fibrillation are independent risk factors of poor prognosis in patients with aortic stenosis.