We reviewed 149 episodes of septicemia caused by X. maltophilia and Pseudomonas spp. occurring over a 15-year period. The incidence of septicemia caused by these organisms increased in recent years and was most frequently associated with central venous catheterization. These infections were occasionally complicated by pneumonia or endocarditis, which was often fatal. Although the survival rate was superior to that seen with septicemia caused by other gram-negative organisms, recurrence of infection was significantly more frequent. Removal of central venous catheters is an essential component of therapy of this infection.