This article aims at reflecting on the creation process of O Pico dos Três Irmãos, Mário de Andrade's (1893 - 1945) interrupted literary essay, preserved in the collection of the writer, at Instituto de Estudos Brasileiros, at Universidade de São Paulo. It proposes to analyze the set of preparatory documents gathered by the author, recovering the analytical and interpretative basis in his study about Manuel Bandeira', Carlos Drummond de Andrade' and Murilo Mendes' poetry. The article discusses some issues regarding the critical and genetic edition of this manuscript.