RESUMO
The uncertainties in the ethiological treatment of Chagas' Disease are consequence of the lack of entire knowledge of its pathogeny and the non existence of a healing criterium. There is a consensus that antiparasite drugs should be used in the acute phase of the infection, regardless of the infection route, in new crisis, in patients under immunossuppression and in organs transplantation. There is still controversy regarding subacute, chronic or undetermined phase or cases with mild cardiac/digestive forms, not included in the situations listed above neither in a research protocol. The treatment includes oral benzonidazol 5 mg/kg/day, bid or tid for 60 days. In 71 patients monitored in this fashion, the authors have found 60 percent of negative xenodiagnostic at the end of treatment. It is still necessary, however, to continue to investigate and accomplishing more randomized trials to confirm the efficacy of such method, and also to try to obtain effective and less toxic agents. It is also fundamental to standardize a more reliable healing criterium.