UNC93B1 associates with Toll-Like Receptor (TLR) 3, 7 and 9, mediating their translocation from the endoplasmic reticulum to the endolysosome, thus allowing proper activation by microbial nucleic acids. We found that the triple deficient ‘3d’ mice, which lack functional UNC93B1 as well as functional endossomal TLRs, are highly susceptible to infection with Trypanosoma cruzi. The enhanced parasitemia and mortality in 3d animals were associated with impaired pro-inflammatory response, including reduced levels of IL-12p40 and IFN-γ. Importantly, the phenotype of 3d mice was intermediary between MyD88−/−(highly susceptible) and TLR9−/−(less susceptible), indicating the involvement of an additional UN93B1-dependent-TLR(s) on host resistance to T. cruzi. Hence, our experiments also revealed that TLR7 is a ritical innate immune receptor involved in recognition of parasite RNA, induction of IL-12p40 by dendritic cells, and consequent IFN-γby T lymphocytes. Furthermore, we show that upon T. cruzi infection triple TLR3/7/9−/−mice had similar phenotype than 3d mice. These data imply hat the nucleic acid-sensing TLRs are critical determinants of host resistance to primary infection with T. cruzi.