Apoptosis or programmed cell death, is a phenomenon with ultrastructural and biochemical characteristics, which is thought to be distinctive from ordinary necrosis. Shrinkage of cells associated with crescent clumps of heterochromatin and formation of membrane-bound apoptotic bodies are thought to represent distinguishing morphologic features. Internucleosomal cleavage of DNA strands reveals a characteristic ladder pattern in gel electrophoresis. Apoptosis is mediated by an active regulatory mechanism, constitutively expressed in normal and neoplastic cells. bcL2, bcl-x, bax, and APO-1/Fas (CD 95) genes are specifically involved in the apoptotic process. Rat thymocytes exposed to glucocorticoids represent a useful model to study cell death. Steroids and peptide hormones play a role in the regulation of apoptosis. Although there is a great interest in monitoring apoptotic process in endocrine cells and their tumors, only a few studies address apoptosis in endocrine glands so far. One goal of future investigation should be directed to explore therapeutic applications.