Background: Mucopolysaccharidoses syndromes are inherited errors of metabolism that are characterized by an increase in tissue glycosaminoglycan concentration. Cardiac involvement has been reported in all MPS syndromes and is a common and early feature in MPS I, II, and VI. Cardiac valve thickening, dysfunction, and hypertrophy are common. Case report: We report the case of a 12-year-old female who complained of dyspnea on exertion persisting for two months associated with pedal edema with morphological and skeletal abnormality. 2D echo suggested severe mitral stenosis. Patient underwent mitral valve replacement. Post-operative period was uneventful and patient was discharged with stable hemodynamics. Conclusion: Although cardiac involvement in MPS is not uncommon, only few case reports of successful cardiac surgeries have been reported. We describe a case of successful mitral valve replacement in a patient with mucopolysaccharidosis.