In the summer of 1967, a relatively complete skeleton of a juvenile was excavated from the Ishkeenickh River Cave Site (now the Ksi Hlginx River) in British Columbia, Canada, dating from approximately 2000 years ago. This individual, likely aged between 10 and 12 years at time of death, displays osteological features consistent with a chronic arthropathy. The most striking pathological changes are on the spine, with bony ankylosis present on several of the cervical and thoracic vertebrae. Lesions can also be observed on the ribs, the ilia, the femora, and a tibia. The arthritic conditions of juvenile-onset ankylosing spondylitis, juvenile psoriatic arthritis, and juvenile-onset adult-type rheumatoid arthritis, along with Klippel-Feil syndrome, are possible aetiologies discussed as part of a differential diagnosis. The presence of post-mortem damage as well as missing bones makes an absolute diagnosis of a disease impossible, however the lesions present on this skeleton seem to be most consistent with juvenile-onset ankylosing spondylitis. The majority of published research on these diseases appears in clinical contexts, therefore this case study represents a unique opportunity to observe the bony changes that occur with juvenile idiopathic arthritis in the context of palaeopathology. (C) 2016 Elsevier Inc. All rights reserved.