In this paper we present the transcription of “Annua histórica de la misión de San Estevan de los indios Lules de 1744”, written by the Jesuit missionary Pedro Juan Andreu. This manuscript belongs to the unpublished De Angelis Collection, which is preserved in the Biblioteca Nacional de Río de Janeiro (BNRJ). The account informs about the material state of the reduction of San Esteban in Western Chaco and the results of two specific tasks requested by the Jesuit Province authorities. It focuses on the description of three indigenous groups –—lules, isistines and omoampas–— from a historical perspective. The document also contains hints we consider relevant to study the interethnic relations in the frontiers of the Chaco region during colonial times. In the preliminary study presented along with this transcription, we first contextualize the manuscript as a historically situated document. Secondly, we identify and examine some of the main data that contributes to the history of the indigenous groups of Chaco in particular and to the frontier studies in general.