Eculizumab is the complement inhibitor administered to ameliorate intravascular hemolysis in paroxysmal nocturnal hemoglobinuria. Whether or not the inhibitory mechanism may also increase the susceptibility to non-Neisserial infection is unclear. A 73-year old woman presented with bacteremia, cholecystitis and liver abscess with Pseudomonas aeruginosa. Although she had been neutropenic for 21 years, she had no history of severe infection before eculizumab had been administered. The infection with P. aeruginosa was successfully controlled with antibiotics, granulocyte colony-stimulating factor and cholecystectomy. The present case might be representative of less common bacterial infections than Neisseria spp. among patients treated with eculizumab.