Among 145 Enterococcus faecalis isolates recovered during a 15-month period (April 1997-June 1998) in AHEPA University Hospital, Thessaloniki, Greece, 94 (65%) exhibited high-level resistance to gentamicin or streptomycin and 61 (42%) to both aminoglycosides; 73% of the high-level aminoglycoside-resistant E. faecalis isolates belonged to a single clone carrying the gene aac(6')-Ie-aph(2")-Ia. These findings differ from those of other regions, where high-level aminoglycoside-resistance genes are dispersed into genetically unrelated strains.