We report the results of the monitoring of resistance to ampicillin, vancomycin, and teicoplanin in enterococci by an Italian network of clinical microbiology laboratories. A total of 16,226 strains were analyzed; 9,169 of these strains were Enterococcus faecalis, 913 were Enterococcus faecium, and 6,144 were Enterococcus species. The average rate of resistance to ampicillin was 1.9% (range, 0-6.5%) for E. faecalis and 70% (range, 33.3%-98.7%) for E. faecium; the average rate of resistance to vancomycin was 1.1% (range, 0.1%-2%) for E. faecalis and 8.5% (range, 0-36.1%) for E. faecium; and the average rate of resistance to teicoplanin was 0.8% (range, 0-2.4%) for E, faecalis and 8.7% (range, 0-36.1%) for E. faecium.