In addition to adult bone marrow–derived mesenchymal stem cells, more recently, a second large stromal compartment found in adipose tissue has received attention and is believed to contain multipotent cells. In vitro, adipose tissue–derived stromal cells (ADS) can differentiate down osteogenic, chondrogenic, myogenic, adipose, and even neuronal pathways. In this article, we explore the effect of fibroblast growth factors 2 (FGF-2) on ADS cells. Our results demonstrated that FGF-2 inhibits osteogenesis in ADS cells. The osteogenic inhibitory effects is dose-dependent and reversible, thus suggesting that the lack of osteogenesis observed in ADS cells exposed to FGF-2 is not due to a negative selection triggered by this factor on a subpopulation of osteoblast progenitors. Furthermore, either overexpression of FGF-2, or continuous FGF-2 treatment sustain the proliferative and osteogenic potential state of ADS cells. Therefore, FGF-2 appears to be a positive regulator of osteoprogenitor cells and a negative regulator of osteoblast differentiation in ADS cells. These FGF-2 functional characteristics may assist with cell selection and enrichment for the purpose of bone tissue engineering.