Although Chryseobacterium indolegenes is a bacterium that is widely distributed in nature, it rarely causes infection in humans. This paper is the first report of septic arthritis caused by this bacterium. A 66-year-old woman was operated on for septic arthritis caused by Streptococcus anginosus. She was operated again due to recurrence of the clinical symptoms on the third week of ampicillin-sulbactam therapy. She was on continuous intraarticular irrigation. No bacterium was isolated from materials taken during operation. While clinical symptoms of the patient resolved after the first days of operation she had high fever on the fourth day of intraarticular irrigation. Aerobic cultures of fluid taken from drainage catheter placed into the intraarticular space and irrigation fluid grew Chryseobacterium indolegenes. Intraarticular irrigation was stopped and antibiotherapy was changed to piperacillin and tazobactam. Clinical status of the patient improved after therapy.