A review was performed of the 57 cases of Klebsiella pneumoniae bacteremia that occurred in children at our institution during a 10-year period. The rate of K pneumoniae bacteremia relative to all blood cultures in which bacteria were isolated was 1.1%. Children younger than 12 months of age accounted for 38 cases (67%). There were 8 children (14%) who were afebrile at the time bacteremia was documented; other presenting clinical features were generally indistinguishable from those that characterize pediatric bacteremia of more common causes. Fourteen children (25%) were receiving broad-spectrum parenteral antibiotic therapy at the time bacteremia was documented. In 53 patients (93%), an underlying condition predisposing to opportunistic infection was identified, the most common of which were lesions of the gastrointestinal tract (56%), presence of an indwelling central venous catheter (35%), and neutropenia (25%). Klebsiella pneumoniae was a constituent of polymicrobial bacteremia in 15 patients (26%). The overall mortality rate associated with this infection was 20%, with over one half of all deaths occurring in infants who were afebrile at the time bacteremia was documented. Klebsiella pneumoniae bacteremia is a relatively uncommon, serious infection that usually occurs in young children with predisposing underlying conditions, and is associated with a significant mortality rate.