The definition of Lutembacher's syndrome has undergone many changes. It refers to combination of congenital Atrial Septal Defect with acquired mitral stenosis. Lutembacher's syndrome is a very rare disease and in the past, it has been either overdiagnosed or misdiagnosed. Here, we will discuss a case of a pregnant lady who developed breathlessness during her third trimester of pregnancy and on detailed examination and investigation, she was found to be having Lutembacher's syndrome