Immune response of Wistar rats, infected with 4000 L1 T. spiralis and treated with P. granulosum during the muscle phase of nematode invasion were measured. The increase of spleen mass was observed in all groups infected and exposed to P. granulosum. Intraperitoneal injection of bacteria results in higher level of T lymphocytes and activated neutrophils. The level of inhibition of macrophages migration was depended on relation to the time and doses of injection. In non-specific stimulated animals there were not statistically significant changes in the level of specific IgG1 antibodies determined by ELISA, against the crude extract of infective larvae of T. spiralis. The reduction of intensity of nematode invasion during the muscle phase was not observed in rats after P. granulosum treatment.