Although a growing literature has investigated how animosity and consumer ethnocentrism change customers’ perceptions of foreign products in developed markets, research examining these effects in developing markets is scarce. Additionally, the role of country of origin on such effects has received far less attention. The current paper is developed to bridge these gaps. The primary objectives of this paper are to examine whether the animosity and consumer ethnocentrism models that work in the Western world could be applied into a developing market like Vietnam, and whether these relationships are moderated by country of origin (USA versus China). Data from 485 Vietnamese customers illustrate that most of the main effects are significant except for the relationship between ethnocentrism and product judgement, and the relationship between cosmopolitanism and willingness to buy. Furthermore, out of the three moderation effects, the influence of country of origin on the relationship between ethnocentrism and willingness to buy is significant. The paper concludes with theoretical and managerial implications, limitations, and future research.