The aim of the study carried out on ten young (10-week old) pigs of the native Polish Large White breed experimentally infected with a low dose of 300 invasive muscle larvae (ML) of Trichinella spiralis was intravital detection of trichinellosis using the E-S ELISA test, determination of a variation level of IgG antibodies against excretory-secretory (E-S) antigens of T. spiralis muscle larvae and finally, describing the intensity of T. spiralis larvae infection in selected muscles. The pig sera were collected at 7 and 9 days prior to the experimental infection with T. spiralis and at 9, 14, 20, 23, 25, 27, 30, 33, 37, 41, 46 days post-infection (d.p.i.). The anti-T. spiralis IgG antibodies were detected by a commercial E-S ELISA test (PrioCHECK Trichinella Ab). Average intensity of the T. spiralis infection in the examined muscles of pigs ranged from 1.52 up to 43.09 larvae/g. The studies revealed that the E-S antigen in the ELISA test did not show cross-reaction with the sera of pigs infected with Oesophagostomum spp. The ELISA assay did not recognize trichinellosis in pigs until 27 days after the T. spiralis infection. The anti-T. spiralis IgG antibodies were first detected on day 30 post-infection. A statistically significant increase of IgG antibodies against T. spiralis ML E-S antigens was first observed between days 27-30 (p<0.01) post-infection, and a further significant rise in the antibody level occurred between days 27 and 33 (p<0.01); 30 and 33 (p<0.01); 33 and 37 (p<0.05) following infection.