Objective: To evaluate the outcome of Left Artrial Reduction by Auto Transplant technique in Giant LA with Mitral valve disease. Methods: This prospective study conducted in the Department of Cardio Thoracic and Vascular Surgery MGM Super Specialty Hospital Indore from 1"September 2022 to 30" August 2023.The aortic and bicaval cannulation was done and CPB instituted followed by cardioplegic arrest of heart. First the root, then the coronary ostia, provided cardioplegia. Transection of the Aorta, PA, SVC, and IVC followed by giant LA mobilization. An excised strip of LA wall and LAA (3-4cm width) was re-sutured with 5-0 prolene. Sutures repaired the SVC, IVC, PA, and aorta. Bleeding from Coseal-secured sutures. Interrupted stiches mobilized and sutured the mediastinal pleura and pericardium to reduce pulmonary vein suture line tension. Patient elective ventilation lasted 48 hours. Results: 10 patients underwent LA reduction. In 6 patients, concomitant Mitral valve replacement was done while in 4 patients concomitant Double valve replacement was done., 60% were in the age group between 33-35 years, and this was followed by the patients in the age group between 25-30 years of age (40%).Out of 5 patients who were included in the study, 8 patients had Atrial Fibrillation and 8 patients had Dysphagia. This was followed by previous history of thromboembolism seen in 4patients. LAA clot was seen in 4 patients. The mean LA size on Pre-Operative ECHO was 74 mm +/- 10 mm ranging from 64mm to 84mm. There was reduction in LA size (from 74+/- 10mm to 48 +/- 6mm) ranging from 42mm to 54mm. Conclusion: Giant LA associated with extra cardiac compressive symptoms should be reduced in size by Auto transplant technique which is safe in expert hands. Giant LA is typically found in patients with rheumatic mitral valve disease with severe regurgitation, Diagnosis is at times possible by routine chest x ray, Echocardiography is an excellent modality to establish its diagnosis, assess and direct correct management.