This article analyses the participation of officers of the Inquisition (inquisitors, prosecutors, secretaries, contador, receivers, alguacil mayor, etc.) in different lucrative activities revolving around the sugar mills of Gran Canaria during the early decades of the 17th century. This involvement led to jurisdictional conflicts and judicial confrontations with certain neighbours, as well as between the inquisitorial members themselves; all of this a far cry from the prevailing image of the Holy Office, or the one it projected about itself. Secondarily, the paper sheds light on different aspects and practices in the world of the sugar business, already in its final phase on the island. [ABSTRACT FROM AUTHOR]