This thesis seeks to be a contribution to a broader debate on how public opinion builds up its perceptions on foreign policy and foreign affairs. Its two main objectives are to examine: (a) which are the determinants that explain public opinion knowledge on foreign affairs; and (b) whether public opinion is sensitive to framing effects on this issue. The analysis was done by mixing quantitative methods and survey experiments, while its novelty is that brings unprecedent evidence from Latin America. The main findings of the thesis are twofold. On the one hand, Latin American public opinion knowledge on foreign affairs is low. In this regard, both traditional individual variables and contextual ones, namely the size of the city, are useful to predict a person's knowledge. On the other, public opinion perceptions regarding foreign policy, either presented on a general or specific way, are sensitive to framing effects. 2013/23251-9 and 2015/12860-0 (BEPE) has been extremely helpful in order to achieve this PhD. Moreover, I would like to thank my advisor Professor Janina Onuki for all her support and being an example of ethics since I arrived to Brazil in 2012. In addition, I would not like to forget of my co-advisor Anthony Pereira and all the staff of King's College London for their warming reception in London. Finally, I would like to mention Professors Vinicius de Carvalho, Gerardo Maldonado and Cristiane Lucena for their valuable comments and suggestions.