This study presents the first two cases of infections with Klebsiella pneumoniae producing extended spectrum betalactamases (ESBL) that have been recorded in Denmark. They presented as a urinary tract infection and a generalized infection in a patient admitted to an intensive care unit. Both patients had been treated with broad spectrum antibiotics prior to infection. Presumably, one of the strains had been imported from Turkey. The ESBL of the two strains were characterized as SHV-2 and SHV-5, respectively. Patients transferred from hospitals abroad should be screened for Klebsiella producing ESBL, in addition to MRSA and other multiresistant organisms. A restrictive antibiotic policy and strict hygienic precautions are essential measures to control the selection and spread of such organisms in the hospital environment.