Sirtuin 2, which is mainly present in cytoplasm, plays an important role in mammalian development, caloric restriction, metabolic regulation cellular antioxidant potential and the regulation of aging. We found that the protein level of sirtuin 2 in human peripheral blood mononuclear cells (PBMCs) decreases with an advance in donor age in men and women. Our data suggest that sirtuin 2 level in PBMCs decreases with age in both men and women and may have a potential as a useful biomarker monitoring health conditions and aging.