Adipose tissue is an important source of angiotensinogen (AGT). Recent evidence shows that a local renin-angiotensinogen system (RAS) is present in human adipose tissue and may act as a distinct system from plasma RAS. In obese patients, the involvement of angiotensin II (angII) as a consequence of increased plasma AGT secreted from adipose tissue has been proposed in the development of hypertension. Another role of AGT via angII in the development of adipose tissue is supported by the following: (i) in vitro, angII stimulates the production and release of prostacyclin from adipocytes, which in turn promotes the differentiation of precursor cells into adipocytes; (ii) ex vivo and in vivo, both angII and (carba)prostacyclin promote the formation of new fat cells; and (iii) AGT -/- mice exhibit a slowing down of adipose tissue development, as compared to wild-type mice. Altogether the data are consistent with an autocrine/paracrine mechanism implicating AGT, angII and prostacyclin in adipose tissue development.