The aging of the population occurs as a result of advances in medicine and technology, and improvement of living conditions and quality of life in general. The Republic of Croatia also follows world demographic trends. Aging is a natural process experienced by every living being, and it implies a physiological decline in physical and mental abilities. Several biopsychosociological theories try to explain aging and describe in more detail how it can improve. Although they overlap in many aspects, there are disagreements associated with the success of aging. Namely, the concept of successful aging is extremely heterogeneous and therefore very difficult to define precisely. Successful aging is an extremely subjective term, which can be defined individually for each individual. However, although there are discrepancies, most theories agree that successful aging requires quality maintenance of physical and cognitive abilities, reduction of the risk of developing disease or disability, and continued participation of older adults in life decisions. Further standardization of methodological procedures is needed to further improve the quality of older adult individuals in the community.