Research on the circulation of artworks between Europe and the Americas superficially examined the role played by Portugal-based individuals in the trade of looted art in the immediate postwar period. Since then, however, cultural studies have ignored the interactions between Portuguese museums and collectors, and refugees and expatriates involved in the trade, as well as the role played by Portugal in the transatlantic circulation of artworks. This article has two goals: first, to examine the lack of academic engagement in the study of the transactions and provenance of artworks in Portugal between 1933 and 1945; second, to ascertain the existence and demonstrate the utility of Portuguese sources in conducting this study, by focusing on what they reveal about art dealer Karl Buchholz. Through an outline of the main areas of research, this article discusses Portuguese academic practice and museum practice. It identifies and contextualizes biases and opens the door for academic attention to Nazi-era provenance research. Portuguese sources illustrating the activity of Karl Buchholz in Portugal between 1943–5 enable a reconstruction of the chronology of his exhibitions in Lisbon and a partial identification of the artworks exhibited.