This article provides an in-depth exploration of early modern ideas of the American tropics in the specific context of colonial Spanish America. Its principal focus is a 17th century treatise entitled Paraíso en el Nuevo Mundo (Paradise in the New World). Written in the mid-17th century by a jurist named Antonio de León Pinelo, the treatise proposes that Eden was once located in the South American tropics. León Pinelo, although born in Spain, considered himself a criollo or Spanish American due to his long years of residence in Peru. Building on studies of criollo consciousness, as well as on recent work that demonstrates the prominence of ideas about the tropics in Iberian colonial expansion, this article intervenes in a rapidly growing academic literature on the genealogies of tropicality since the early modern era. In doing so, it highlights the importance of recognizing criollo writers as producers of distinctive discourses of tropicality that reflected and responded to their ambivalent subject positions and their political and personal aims. First, the article illustrates how León Pinelo’s argument about paradise involved the construction of a comparative tropical geography and the sketching out of a distinctive New World tropicality. Second, it examines León Pinelo’s embrace of negative as well as positive elements in his depiction of American tropical nature and suggests that his incorporation of negative phenomena was intended to lend weight to his argument about paradise. Third, the article considers how the author’s representations of a tropical New World Eden were inflected by his Spanish American patriotism as well as by his role as an agent of empire situated in Madrid.