Abstract: Heat shock protein (HSP) constitutes an endogenous stress response that protects cells from injury. Most research on this important protein has focused on the immediate response to acute stress in cell culture systems and mammalians. Circulating HSP70 is present in the circulation of healthy individuals and in patients with various disorders, including heart failure (HF). HSP70 levels are elevated in chronic HF patients, particularly in those with cardiac cachexia. HSP70 relates to the disease severity and not to the survival rate. The significance of the relationship of HSP70 expression and morbidity in HF needs further evaluation.