Aging is caused by gradual accumulation of cell and tissue damage. Accumulation of damage begins early and continues progressively throughout life, resulting after several decades in the overt frailty, disability and diseases associated with aging. In Serbia during the last few years, several different institutions participated in the investigation in the aging process: (1) Changes in hormone signaling with aging-the age-related increase in insulinemia and glucose metabolism deregulation was found to be attributed to changes in insulin signaling as demonstrated on murine models. (2) Changes in immunological response in aging-along with involution of thymic lymphoepithelial tissue, it has been demonstrated on a murine model that early thymocyte differentiational steps within the CD4-8-double negative developmental stage are age-sensitive. (3) Changes in cholesterol metabolism and oxidative processes in aging-the beneficial effect of long-term dietary restriction on ageing, was explained as effect on cholesterol metabolism. (4) Alzheimer's disease-the connection between neurodegenerative processes associated to the Alzheimer's disease and the function of the Na-K-ATPase which is known to be altered by ageing has been experimentally shown.The recent work of Serbian investigators suggest some new evidence that aging process influences the hormone signaling, immunological response, cholesterol metabolism and oxidative processes.