Galectins--lectins binding β-galactosides their properties and biological role have been described. Galectines family in mammalians consists of 15 members. Galectin-3 is atypical specimen of galectins family. Its participation in fibrosis, cardiac remodeling, immune and inflammation responses have been shown. Employment galectin-3 as new independent biomarker for diagnosis of acute heart failure and outcome predictor in patients with chronic heart failure (HF) are discussed. Diagnostic and prognostic values of galectin-3 are compared with famous and wide using HF marker NT-proBNP. Combined employing biomarkers for diagnostic and prognostic purpose of HF have been discussed. Using galectin-3 as therapeutic target in treatment of chronic HF in future is suggested.