We report results of PCR-DNA based detection of Trypanosoma cruzi in wild mammal reservoirs from a chagasic area of Chile. We analyzed 157 blood samples from wild mammals including the marsupial Thylamis elegans and the rodents Octodon degus, Phyllotis darwini, and Abrothrix olivaceus. In addition, 42 blood samples from goats (i.e., a peridomestic mammal) were analyzed. Blood samples were used to extract DNA, and PCR was performed using the amplification of minicircle DNA sequences. Southern analysis was used to confirm diagnosis with a universal probe of P(32)-labeled kinetoplast DNA. Altogether, 51% of the wild and 36% of the peridomestic mammals were infected with T. cruzi. These findings suggest that the real T. cruzi infection levels in wild and peridomiciliary reservoirs are higher than those previously determined with serological and parasitological conventional methods. The relevance of our results is discussed in term of the risk factor of infection in human.