Giant left atrium (GLA) is a condition defined when the left atrial diameter exceeds 65 mm. GLA is commonly associated with mitral valve regurgitation due to excess intracavitary pressure resulting in strain and dilation of the left atrial chamber. The mechanism of lone GLA remains unknown but is possibly related to inherent weakening of the atrial wall tissue. The enlarged left atrium leads to expansion of left atrial volume, which in turn can place pressure on the main bronchus, lung, and left ventricle with corresponding cardiopulmonary embarrassment. Because GLA can increase the risk of sudden death, its existence merits careful evaluation and surgical intervention when needed. Careful review of the literature reveals that the presence of GLA in the context of severe mitral valve regurgitation with or without atrial fibrillation is the most common indication for surgical intervention. Indications for intervening on lone GLA are rare except when compressive symptoms manifest. Partial resection of inferior and or superior left atrial wall is the most common surgical technique. With the evolution of atrial fibrillation surgery, atrial size matters and is determinant of long term performance following successful ablation. Surgical management of GLA achieves good clinical outcome with respect to cardiopulmonary performance including restoration of sinus rhythm among patients suffering from atrial fibrillation. Surgeons should be aware of current modalities for atrial volume reduction when indicated to retain the function and structure of the left atrium.