Summary. Heart failure is a clinical syndrome characterized by abnormalities of cardiac, skeletal muscle, and renal func- tion, stimulation of the sympathetic nervous system, and a complex pattern of neurohormonal changes. Early diagnosis and treatment of heart failure are important factors in reducing morbidity and mortality associated with the disease. During the past several years many studies have demonstrated that natriuretic peptides are the biochemical markers of choice for diag- nosing and risk stratification of patients with chronic heart failure. The value of natriuretic peptides has already been recog- nized by their inclusion in the recent European guidelines for the diagnosis of chronic heart failure. The natriuretic peptides family is comprised of four peptides, each with common 17 amino acid ring structure. The tissue-specific distribution and regulation of each peptide are different. At present, there is no consensus on the most reliable method for natriuretic peptides assay, although non-competitive immunoassay may be more suitable for clinical routine than competitive assay.