This thesis explores the effect that nationalism had on the spread of communism to Vietnam and Cuba during the first half of the twentieth century. Using a case studies approach to analyze the revolution of Ho Chi Minh in Vietnam and Fidel Castro in Cuba, the thesis seeks to determine the extent to which nationalism directed these revolutions and their turn to communism once assuming power. The study examines the conditions that existed in each country that allowed for a nationalist revolution to be successful, and the beliefs and rhetoric of Ho Chi Minh and Fidel Castro, the primary figures of each revolution. The thesis seeks to add to the research conducted on the power that nationalism had in the Third World from the early 1900s to 1960, and it wishes to contribute to the factors that must be considered by foreign policy makers when pursuing military action or nation-building abroad. The research shows that nationalism played a significant role in bringing communism to Vietnam and Cuba, yet due to the difficulty in measuring a core human feeling like nationalism, other factors cannot be discounted.