The aim of the study is to evaluate the clinical application in veterinary orthopedics of bone marrow mononuclear cells (BMMNCs) and cultured bone marrow stromal cells (cBMSCs) for the treatment of some orthopaedic lesions in the dog. The authors carried out a clinical study on 14 dogs of different breed, age and size with the following lesions: 1 bone cyst of the glenoid rime; 2 nonunion of the tibia; 3 nonunion of the femur; 2 lengthening of the radius; 1 large bone defect of the distal radius;1 nonunion with carpus valgus; 4 Legg-Calvé-Perthés disease. In 9 cases the BMMCNs were used in combination with a three dimensional resorbable osteogenic scaffold the chemical composition and size of which facilitates the ingrowth of bone. In these cases the BMMNCs were suspended in an adequate amount of fibrin glue and then distribuited uniformly on a Tricalcium-Phosphate (TCP) scaffold onto which were also added some drops of thrombin. In 1 case of nonunion of the tibia and in 3 cases of Legg-Calvè-Perthés (LCP) disease the cultured BMSCs were used instead because of the small size of the dogs and of the little amount of aspirated bone marrow. X-ray examinations were performed immediately after the surgery. Clinical, ultrasounds and X-ray examinations were performed after 20 days and then every month. Until now the treated dogs have shown very good clinical and X-ray results. One of the objectives of the study was to use the BMMNCs in clinical application in orthopaedic lesions in the dog. The advantages of using the cells immediately after the bone marrow is collected, are that the surgery can be performed the same day, the cells do not need to be expanded in vitro, they preserve their osteogenic potential to form bone and promote the proper integration of the implant with the bone and lastly, the technique is easier and the costs are lower.