Once multipotent mesenchymal cells become committed to the adipoblast lineage, adipogenesis, the process of preadipocytes differentiation into adipocytes is initiated. This process starts with a phase of exponential growth of adipoblasts. Following confluence of these adipoblasts, the cells enter into a cell cycle arrest, they re-enter the cell cycle and pass through a limited number of cell divisions, and finally differentiate into fully mature adipocytes. Adipogenesis is controlled by a complex cross-talk between positive and negative regulators, such as hormonal and nutritional stimuli, that change the activity of a selected set of transcription factors. Regulation of adipogenesis is crucial to keep the body energy balance because a limited amount of adipose tissue, lipodystrophy, or an excess of adipose tissue, such as occurs in obesity, lead to profound metabolic dysfunctions and disease.