Seventy four patients underwent tricuspid valve replacement (TVR), between 1968 and 1983. 93% were female, mean age was 44 +/- 4 years. Tricuspid valve was replaced with a mechanical prosthesis in 52 and a bioprosthesis in 22 patients. Fifty seven patients underwent primary TVR and 17 underwent a secondary TVR following a mean interval of 41 +/- 2 months (SEM) following a previous mitral or tricuspid valve operation. Preoperatively 86% patients were in NYHA class III-IV and congestive cardiac failure (CHF). Early mortality for primary TVR was 36.8% and 35.2% for secondary TVR. Early mortality has been significantly reduced since the introduction of cardioplegic protection for the associated valve lesions. Early mortality was significantly influenced by the reduced preoperative values of FVC and FEV1 in patients with long standing mitral valve disease and by raised preoperative levels of plasma bilirubin and alkaline phosphate in patients with CHF. Risk of thrombotic occlusion and late deaths remained high during the first year after TVR with a mechanical prosthesis.