From April 1993 to May 1997, 21 patients underwent surgical treatment for prosthetic valve endocarditis (PVE). There were 13 males and eight females aged from 46 to 79 years old (mean 62 years). There were four cases of early PVE (onset of PVE within 60 days from previous valve replacement), and 17 cases of late PVE (after 60 days). The predominant organisms were Staphylococcus epidermidis (eight cases), Staphylococcus aureus (two cases), MRSA (one case), streptococcal species (three cases), Candida (two cases), Pseudomonas cepacia (one case) and Enterococcus (one case). The predominant organisms were identified in 16 of 20 cases by preoperative blood culture, and in 11 of 20 cases by intraoperative tissue culture, and in 19 cases in all. There were four cases of preoperative cerebral complications, and three cases resurged. The hospital mortality rate was 24% (five patients). Reoperation was required in four patients for recurrence of PVE. Autopsy was performed in four of five patients. Intramyocardial abscess was detected in three patients. Earlier diagnosis and earlier surgical treatment could prevent emboli due to vegetations, which might cause catastrophic results, and could achieve better outcomes. Identification of the predominant organisms, especially from operative tissue cultures, is required.