Trichinellosis is a zoonosis acquired by the ingestion of undercooked meat containing the infective larvae of Trichinella spiralis (T. spiralis). Despite veterinary public health efforts to control it, re-emergence of the disease has been observed in many areas of the world in the past 10–20 years. Although ivermectin (IVM) achieved high efficacy as larvicidal in trichinellosis, the possibility of disease transmission to other hosts is still present that will hinder the eradication of that serious disease. Therefore, our goal is to determine the efficacy of IVM on the subsequent infectivity of T. spiralis larvae in experimental animals through parasitological and biochemical studies of the intestinal phase. We found that the proinflammatory cytokine; interleukin-1β (IL-1β) and epithelial neutrophil activating peptide 78 (ENA-78) mRNA expression were decreased in group II which was infected by IVM- treated T. spiralis larvae on the 5th day post infection, also the same group showed the lowest levels of vasoactive intestinal peptide (VIP) and protein carbonyl (PCO) as well as the lowest activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) enzymes. The lowest adult and larval counts were observed in group II at the 5 th day post infection with highly significant differences in comparison to other groups. In conclusion, IVM appears to affect the infectivity of T. spiralis larvae with subsequent decrease of T. spiralis adults and total larval count. These effects were more pronounced when IVM was given early in the infection. IVM is feasible and useful drug in the treatment of current infection and control of subsequent infections with T. spiralis.