A case of congenital, isolated tricuspid regurgitation is reported. A 48 year old woman has been admitted because of shortness of breath and progressive fatigue. Although the heart murmur had been heard in her childhood, the first symptoms appeared when she was 25. One year later she underwent a plastic surgery of tricuspid valve. During the following 20 years she remained asymptomatic, until dyspnea and fatigue developed again. On admission she was cyanotic and positive, systolic jugular venous pulse was seen. Atrial flutter was present and no systolic cardiac murmur was heart. The liver was enlarged without peripheral oedema. Echo-Doppler examination and cardiac catheterisation revealed huge right cardiac chambers and significant tricuspid regurgitation. During reoperation a valve consisting of only two cusps was found with extremely dilated valvular anulus. A Bex valvuloplasty was successfully performed. One month later a control echo-Doppler showed the diminution of right ventricle and right atrium with hardly visible regurgitant jet. The pathogenesis and the course of this extremely rare disease have been also discussed in the paper.