In this essay we analyze Gonalves Diass poem I-Juca-Pirama as an expression of the scientific discourse in vogue at the time it was written, in 1851. The poem privileges the image of the Brazilian Indian as a good-savage; however, its ethnographic contribution is also a topic that needs to be discussed. The details that the author provides and the historical notes he includes make the poem almost a diorama of the anthropophagic rituals practiced by many Brazilian indigenous tribes. In the poem I-Juca-Pirama there are two voices, a lyrical (or epical) voice and a scientific-anthropological voice, which is present on the notes. These voices do not challenge each other, but they are both very authoritative. The lyrical-epical voice is well-known as one of the greatest romantic voices of Brazilian poetry. The scientific-anthropological voice of the notes, on the other hand, is almost a historical document that validates the legend of the good-savage, which became one of the most important motes of the Brazilian romanticism. In other words, the voice of the notes attempts to bring the poem closer to reality, and thereby makes it a form of historical account.