The aim of this study was to determine whether synovial fluid (SF) of dogs contains cells that have characteristics of MSCs and to describe their differentiation potential. SF adherent cells from 5 young German shepherd dogs (average 3.8 ± 0.9 years) were expanded (37°C, 5% CO2, humidified atmosphere) three weeks before their phenotype was characterized by flow-cytometry for the presence of CD90 and CD34. Population doubling time (PDT), number of CFU-F and adipogenic, osteogenic and chondrogenic potentials have been determined