After more than two decades of cardiac valve replacement surgery, the number of reoperations has increased and third or even fourth replacements are no longer rare occurrences. Of the 2072 valves prostheses implanted at the Hôpital Foch between 1970 and December 1984, 134 (6.4%) have been changed at least once and 27 prostheses (1.3%) have been replaced three or more times in 23 patients. Eighteen patients were operated on three times and 5 patients 4 times, a total of 73 operations. Ten patients had aortic valve prostheses, 7 had mitral valve prostheses and 6 had double aortic and mitral valve prostheses. The technical difficulties due to previous cardiac surgery were not great or easily surmounted as every procedure was performed by a median sternotomy and only 2 out of 50 required cannulation of the femoral vessels for cardiopulmonary bypass. The repair itself consisted of simple valve replacement in 3 out of 4 cases (30 single and 3 double valve replacements, 3 valve reinsertions). The other operations required more complex techniques such as remodelling of the ring of insertion or the use of a valved tube. None of the patients died in the operating theatre. However, 3 patients died during the hospital period (13%) and there were 2 late deaths (10%) and 1 patient (5%) was lost to follow-up. The 17 survivors were followed up for 3 to 148 months (average 42 months). Half the patients are now in functional Classes I or II of the NYHA classification. These results show that repeated valve replacement has an acceptable operative risk.(ABSTRACT TRUNCATED AT 250 WORDS)