Seventeen Klebsiella pneumoniae clinical isolates carrying the blaVIM-1 metallo-β-lactamase gene were collected in the intensive care units of three hospitals in Athens, Greece, in 2002. They exhibited various carbapenem resistance levels (Etest MICs of imipenem ranged from 4 to 32 μg/ml). All isolates gave positive results by the imipenem-EDTA synergy Etest. The isolates were classified into four main types by pulsed-field gel electrophoresis; the majority of the isolates (5 and 10 isolates) belonged to two types. The blaVIM-1 gene cassette was part of the variable region of a class 1 integron that also included aac6, dhfrI, and aadA. This structure was carried by transferable plasmids.