MINI-ABSTRACT:: Forty-seven-year-old woman presented with NYHA class III symptoms of dyspnea on exertion with acute right lower limb ischemia, prompt surgical embolectomy was performed. Cardiac evaluation with echocardiography and 3D echocardiography revealed rheumatic heart disease—severe mitral stenosis with a giant left atrium with large mass occupying almost whole of left atrium. Detailed evaluation of the mass was performed to rule out malignancy with transesophageal echocardiography, computed tomography, and magnetic resonance imaging which were indicative of thrombus. Left atrial thrombectomy with mitral valve replacement was carried out, and histopathology confirmed the diagnosis of thrombus.