The authors describe the occurrence of an authoctonous case o Chagas' Disease in São Francisco do Pará, aproximately 95 km from Belém city, Pará State. This case constitutes the 11th in Pará an the 29th in the Amazonian Basin. The patient, a boy seven years old, was serologically and parasitologically positive for T. cruzi. The strain was characterized by enzyme electrophoresis as zymodeme 3 of. T. cruzi.