Mesenchymal stem cells (MSC) are multipotent cells, which are able to differentiate into various cell types of the body, as for example in osteogenic, chondrogenic, adipogenic and myogenic directions. In human medicine, the application of stem cells represents a well-established clinical procedure already applied for several decades. Addition-ally, in veterinary medicine, the stem-cell field is a rapidly growing sector for clinical use, particularly in horses. Recently, this treatment moda lity has also been commonly applied in dogs. The main field of application are diseases of the musculoskeletal system. Furthermore MSC are predominantly used for the treatment of lameness because of osteoarthritic changes of the large joints. In veterinary medicine, MSC are mainly isolated from bone marrow or adipose tissue. This artic le provides an overview of the removal site, isolation, characterisation and application of MSC. Moreover, studies available in the litera ture concerning the therapy of orthopaedic diseases in the dog using MSC are presented.