A retrospective case study was done to determine the long term outcome of surgery in dogs treated for canine hip dysplasia with a triple pelvic osteotomy (TPO). Twenty four dogs with bilateral hip dysplasia that had had a unilateral TPO performed between January 1988 and June 1995 were assessed at the Ontario Veterinary College. Assessment included a physical, orthopedic and lameness examination, standard blood work, pelvic radiographs and force plate gait analysis. These dogs were compared to bilaterally dysplastic dogs with no surgical treatment and clinically normal dogs. Coxofemoral joints with a TPO showed significant improvement in Norberg angles and subluxation scores but still developed degenerative joint disease as early as 12 months after surgery. The degree of degenerative joint disease and instability increased significantly from the pre-operative to the follow-up time in the operated limbs. The degree of DJD was generally less, although not significantly so than that in the contralateral unoperated limbs. Despite development of DJD the TPO limbs bore more weight and transferred more force as shown by force plate assessment, peak vertical force (PVF) and mean vertical force over stance (MVF). Following TPO, dogs did not have significantly less lameness or joint pain in the operated hip compared to the unoperated hip or compared to the unoperated dysplastic or control dogs.