This chapter will present innovative methods for the isolation and characterization of mature, primary bone marrow adipocytes from rodents. The key advantage of this protocol is that it allows for ex vivo analyses of mature bone marrow adipocytes, which is a more direct approach than traditional in vitro studies. While the difficulty in isolating mature adipocytes from the heterogenous bone marrow population has precluded their characterization in many preclinical studies, we have optimized our methods to maximize the collection of alive, mature bone marrow adipocytes and minimize contamination of other bone marrow and immune cells.