The aim of the study was to characterize the antiparasite humoral response in patients with the syndrome of visceral larval toxocarosis. Specific IgG, specific IgE and total IgE immunoglobulins against Toxocara canis excretory/secretory antigens (TES) were detected by using ELISA technique. Antibody response was studied in complete sera as well as in immunoglobulin fractions (IgG and IgE), isolation of which was performed on Protein A Sepharose. It was observed that removal of IgG from the serum samples resulted mostly in increasing levels of anti-Toxocara IgE antibodies what agrees with the theory of the blocking effect of IgG in the immune response. The results demonstrated a little correlation between slgG and slgE in the sera of symptomatic patients, examined in ELISA reaction.