We report here the case of a sacro-iliitis due to Kingella kingae in a 35 year-old patient. This case report points out the pathogenic potency in adults of this organism which is known as a cause of invasive infections in young children. Inoculation of blood culture vials with clinical specimens and the use of nucleic acid amplification have recently improved the sensitivity to identify Kingella kingae and to diagnose infections which need an efficient antimicrobial therapy.