Congenital tricuspid valve disease is a rare defect that includes regurgitation, stenosis and Ebstein's anomaly. We report a case of severe tricuspid regurgitation associated with functional mitral regurgitation in a 47-year-old man with congestive heart failure. Transthoracic echocardiography (TTE) ruled out any Ebstein's anomaly. Three-dimensional TTE revealed a ‘tricuspid hole’ into the anterior leaflet that was only attached to the tricuspid annulus next to both anteroseptal and anteroposterior commissures. There was no sign of leaflet tear or perforation. The surgical repair of the tricuspid and mitral valves was performed with an optimal result. No sign of endocarditis or rheumatic disease was observed during the intervention. Sequence analysis of GATA4, HEY2 and ZFPM2 genes was performed, but no causative mutation was identified.