Galectins belong to the family of galactose-binding proteins known to play an important role in the processes of cell proliferation, differentiation, migration and neoplastic progression. Herein, we studied the expression of galectin-3 (Gal-3) in chronic lymphocytic leukemia (CLL).The expression of Gal-3 was analyzed by means of multiparametric flow cytometry in normal and pathological B-cells from peripheral blood and bone marrow samples of 67 patients with CLL.Pathological B-cells expressed significantly higher levels of cytoplasmic Gal-3 than normal B-cells. Moreover, overexpression of cytoplasmic Gal-3 was observed in the prognostically poorest subgroup of CLL patients, namely those with 17p deletion.Our results indicate a possible role of galectin-3 in CLL pathophysiology and its potential value as a prognostic marker and therapeutic target.