To show that the conversos’ ability to become an integral and influential part of local society did not depend on their inner, private religious and ethnic identities but rather on external factors, the present article analyzes the case of the New Christians in colonial Cartagena de Indias (in today’s Colombia) based on testimonies found in Inquisition archives. The peculiarity of Cartagena de Indias, in contrast to other important cities in the Hispanic colonies, relied on the fact that it was a small city with a relatively small Caucasian population, and its economic life depended almost exclusively on commercial activity. The thesis defended in this article argues that if commerce was central to life in Cartagena de Indias, and the Portuguese New Christians predominated both demographically and in the field of trade, clearly their influence on various aspects of local society had to be significant. The article presents specific examples that show the Portuguese impact in the city in different spheres of society, including the social, political, economic, and philanthropic.