Ebstein's anomaly (EA) is a rare congenital heart defect, characterized by an anomalous tricuspid valve displaced towards the apex of the right ventricle (RV); it is usually accompanied by regurgitation. While its severe forms with an extremely dilated functional RV and oppression of the left heart chambers result in the development of severe heart failure at a young age and, in some cases, even prenatally, patients with mild EA may live until old age with the condition unrecognized. We present the case of a patient with a milder form of EA and a contribution of dysplasia, with the disease undiagnosed until his eighties when he developed heart failure accompanied by significant tricuspid regurgitation. Tricuspid valve replacement with a bioprosthesis and atrial septal defect occlusion were followed by significant improvement of RV function and remission of the patient's problems.