Left atrial dimensions and volumes are considered valuable prognostic markers in various conditions like hypertension, obesity, atrial fibrillation, chronic kidney disease, sleep apnea syndrome, mitral valve disease, LV systolic and diastolic dysfunction etc. They are also described as strong predictors of major cardiovascular adverse events. Left atrium is difficult to detect by clinical examination. 2D echocardiography helps in quantifying this chamber. It is also the best method for assessment and follow–up of left atrial size in various disease states. The method also has an added advantage of being radiation free and does not require contrast enhancement. Left atrial dilatation, which is a hallmark of left atrial structural remodeling can happen because of both pressure and volume overload. Also, left atrial dilatation can indicate raised LV filling pressures. In this article, we attempt to define the left atrial dimensions and volumes by 2D transthoracic echocardiography in normal Indian adult population. The information thus obtained will help us understand the abnormal which can have prognostic implications.