Twenty-eight children with septicaemia and positive blood cultures for Klebsiella pneumoniae were retrospectively studied and compared with 190 children with sepsis caused by other organisms, identified or not in blood cultures. Septicaemia due to Klebsiella pneumoniae occurred more frequently in children older than 2 years of age, especially those who had an underlying disease and, therefore, were malnourished or had an impaired immune defense system that had required invasive procedures and previous hospitalization. Although the case fatality rate was high in both groups, Klebsiella pneumoniae did not contribute to elevate the relative risk of death. In this study, Klebsiella pneumoniae isolates were highly sensitive to colistin (92.9%) and cefoxitin (82.1%), but poorly sensitive to third generation cephalosporin and imipenen.