The role of platelet-rich plasma (PRP) in promoting the healing of bone fractures has notyet been clearly stated. The aim of this prospective clinical study was to evaluate the effectiveness ofplasma rich in growth factors (PRGF, a PRP derivate) in the treatment of naturally-occurring bonefractures in dogs. With this objective, sixty-five dogs with radius/ulna or tibia/fibula bone fractureswere randomly divided into two groups (PRGF and saline solution (SS) groups) and checked atdays 0, 7, 14, 21, 28, 35, 42, 49, 56, 60, 63, 70, 120, and 180. All the fractures were treated with anexternal skeletal fixation, and pain was controlled with Carprofen. Healing was evaluated by physicalexamination, limb function, radiography, and by a Likert-type owner satisfaction questionnaire.A faster fracture healing was observed in the PRGF group, with statistically significant differenceswith respect to the SS group. Swelling at the fracture site was significantly greater at day 14 and28 in animals injected with PRGF, and more pain on palpation was found in the area at day 28.The injection of PRGF in acute bone fractures accelerates bone healing.