While patellar luxation is one of the most common orthopedic problems in dogs, it has been rarely reported in the literature compared to canine PL studies in cats. The condition affects primarily small/toy breed dogs, however the prevalence of which appears to be increasing in large breeds. Most cases are considered developmental with anatomical deformities leading to failure of the stifle extensor mechanism. Joint pathology increases with age and luxation grade, and surgical correction should be performed at the earliest opportunity to limit further development of skeletal abnormalities or degenerative joint disease. Surgical techniques available for the correction of PL in dogs include femoral trochlear sulcoplasty, tibialtuberosity transposition (TTT), soft tissue imbricationand/or release, and femoral corrective osteotomies. The same techniques are used for correction of PL in cats. A novel method of treating femoro-patellar instability in association with severe femoro-patellar osteoarthritis, by substituting the femoral trochlear with a patellar groove replacement prosthesis is reported. Patellar groove replacement (PGR) is the surgical technique that is used to replace the trochlear groove with an artificial prosthesis. In this pilot study, clinical status and the surgical technique and outcomes of applying the PGR of 2 dogs, and 1 cat which were referred to Istanbul University, Faculty of Veterinary Medicine, and Department of Surgery with the complaint of hindlimb lameness and diagnosed with 3rdand 4th degree patellar luxation, were assessed.