Obesity has reached pandemic dimensions with more than half a billion adults affected worldwide. Detailed knowledge of adipose biology is required for the development of urgently needed novel therapies directed against obesity. Two types of adipose tissue can be distinguished in humans and mice: white adipose tissue (WAT), which primarily stores energy in the form of lipids and has endocrine functions. In contrast, brown adipose tissue (BAT) dissipates energy in the form of heat (thermogenesis). Recent studies in humans demonstrated that BAT not only plays a role for non-shivering thermogenesis in newborns but is also metabolically active in adults. Here, we describe protocols for the generation of cellular models for the analysis of adipogenesis as well as function of brown and white fat. These models are based on the in vitro differentiation of mesenchymal stem cells (MSCs) isolated from adipose tissues. Using specific differentiation protocols, the role of cGMP signaling in both brown as well as white adipocytes can be studied.