Mammalian target of rapamycin (mTOR), a main protein kinase in the phosphoinositide 3-kinase/Akt/p70S6K signaling pathway, is an important intracellular mediator involved in multiple cellular functions including proliferation, differentiation, apoptosis, longevity, tumorigenesis, and angiogenesis. Alterations of the normal activity of mTOR and of mTOR-related kinases in this pathway have been found in a diversity of human tumors, suggesting that mTOR may be an attractive target for the development of new anti-cancer therapies. The main objective of this article is to summarize the available pre-clinical and clinical data regarding a possible role of mTOR inhibitors in the treatment of different endocrine cancers.