Twenty-five patients (21 females, four males; mean age 50.5 ± 13.4 years; range: 23-71 years) underwent tricuspid valve replacement (TVR) with CarboMedicsā valves. The mean number of previous cardiac operations was 0.96 ± 0.84. Concurrent mitral valve replacement was performed in 17 cases (68%). The hospital mortality rate was 24% and late mortality rate 12%. Seventeen early survivors (13 females, four males) were followed up for 46 ± 28 months (range 4-96 months). Mean and peak transvalvular gradients were 4.0 ± 1.7 and 7.9 ± 3.3 mmHg, respectively. Non-therapeutic INR levels were observed in 58.8% of patients. Five patients (29.4% of mid-term survivors) experienced a total of 13 episodes of obstructive valve thrombosis, mostly with inappropriate anticoagulation. One patient required emergency re-do surgery; the others responded initially to thrombolysis or intensified antithrombotic treatment, but experienced at least two additional relapses. Aside from thrombotic episodes, all patients but two were in NYHA functional class II-III, and all but four required diuretics. TVR with mechanical bileaflet valves is associated with high perioperative mortality and mid-term morbidity, and a high incidence of valve thrombosis among patients with poor or fair anticoagulation.