Resumo. This study aimed to verify the occurrence of bloodstream infections caused by Klebsiella spp. and evaluatethe production of extended spectrum ß-lactamases and the factors associated with bloodstream infectionsin patients admitted to the Hospital of the Federal University of Grande Dourados, Dourados/MS. It wasdeveloped through a retrospective analysis of medical records of patients admitted from January 2008to September 2009. We obtained 22 cases of bacteremia caused by Klebsiella spp. Extended spectrumß-lactamases were identified in 68.2% of the isolates. It was found that 91.0% of patients were admittedto the Intensive Care Unit, and 45.5% of the patients were infants under one year old. Among the casesof bacteremia 22.7% died. Invasive procedures such as phlebotomy, tracheostomy and surgery were thefactors most related to the occurrence of bloodstream infections by Klebsiella spp. With regard to bacterialresistance, 86.3% of Klebsiella isolates were resistant to more than 10 antibiotics. Imipenem was the mosteffective since 86.3% of the isolates were sensitive to this antibiotic. Klebsiella β-lactamase-producingextended-spectrum is an important pathogen causing bloodstream infection in patients admitted to ourhospital, especially those in the pediatric intensive care unit. The detection of multidrug-resistant bacteriain blood cultures and evaluation of their susceptibility profile provides important data for the streamliningof antimicrobial therapy, reduced mortality rates and aids in control of hospital infections.