Intra-abdominal infection due to Chryseobacterium meningosepticum is rare, and bacteremia complicated with pleural effusion and retroperitoneal hematoma caused by C. meningosepticum has not been reported previously. A 57-year-old diabetic man presented with bacteremia with retroperitoneal abscess and pleural effusion caused by C. meningosepticum on the 12th day of hospitalization. His clinical condition improved after antimicrobial therapy with levofloxacin and rifampin, debridement of the retroperitoneal hematoma and left-side chest tube insertion. Antibiotics were administered for 1 month, and he was later transferred to a local respiratory care ward under afebrile condition. C. meningosepticum should be included in the list of suspected nosocomial infections, especially in patients with immunocompromised status. Administration of appropriate antibiotics, such as quinolone, minocycline, trimethoprim-sulfamethoxazole or rifampin, and treatment of local infection improve the clinical outcome of patients with C. meningosepticum infection.