Cardiovascular disease is a major cause of morbidity and mortality of older Americans. We have demonstrated recently that centenarian offspring, when compared with age-matched controls, avoid and/or delay cardiovascular disease and cardiovascular risk factors. Given recent evidence suggesting that higher circulating levels of HSP70 predict the future development of cardiovascular disease in established hypertensives and a recent study demonstrating a decrease in HSP60 and HSP70 with advancing age, we hypothesized that HSP70 levels would be lower in centenarian offspring compared with controls. The circulating serum concentration of HSP70 in 20 centenarian offspring and 9 spousal controls was analyzed using a modified HSP70 ELISA method. Centenarian offspring showed approximately 10-fold lower levels of circulating serum HSP70 compared with spousal controls (P <.001). The exact biological significance of the extremely low levels of circulating serum HSP70 observed in centenarian offspring thus far is not clear. However, circulating HSP has been shown to correlate in diseases or disorders in which there is destruction or damage to target tissues or organs, including cardiovascular diseases and numerous autoimmune disorders. We hypothesize that low levels of circulating serum HSP70 may be an indicator of a healthy state and point to longevity of the host; therefore, our results suggest that levels of circulating serum HSP70 may be a marker for longevity.