Ancylostoma ceylanicum is a zoonotic soil-derived nematode that parasitizes the intestines of humans and animals (dogs and cats), leading to malnutrition and iron-deficiencyanemia. Helminth parasites secrete calreticulin (CRT), which regulates or blocks thehost’s immune response. However, no data on A. ceylanicum calreticulin (Ace-CRT) areavailable. We investigated the biological function of recombinant Ace-CRT (rAce-CRT). rAce-CRT showed reliable antigenicity and stimulated the proliferation of mouse splenocytes and canine peripheral blood mononuclear cells. Quantitative reverse-transcriptionPCR assays revealed that rAce-CRT primarily promoted the expression of T helper 2 cytokines, particularly IL-13, in canine peripheral blood lymphocytes. rAce-CRT inhibitedcomplement-mediated sheep erythrocyte hemolysis in vitro. Our findings indicate thatAce-CRT plays an immunomodulatory role and may be a promising candidate moleculefor a hookworm vaccine.