The aim of the study was to reduce of the immunoreactivity of cow milk proteins, present in WPC-65 (α-lactalbumin i β-lactoglobulin) and sodium caseinate (α-, β-, κ-casein) as a result of enzymatic hydrolysis prepared with Alcalase 2.4 L, Novo Nordisk (Bacillus licheniformis), pronase – (Streptomyces griseus protease), papain – EC 3.4.22.2, pepsin (E.C. 3.4.23.1) (Sigma), and LactozymuTM3000 L HPG (Novo Nordisk). The analysis was carried out by ELISA methods, 2D electrophoresis, gel chromatography, sensory analysis and mass spectroscopy. The immunoreactivity of selected hydrolysates and hypoallergenic formulas (Profylac and Nutramigen) was compared using of CMA patients sera. It was concluded that there is possiblity to obtain hypoallergic product based on low molecular fraction of WPC-65 Alcalase-pronase hydrolysate.