In this article, we identify the main characteristics of the advertising included in the Vanguardia magazine (1941-1942) and the Combate (1944) and Tinchera (1946) newspapers, all of them publications linked with the Communist Party in Costa Rica. It also considers the specific details of the individuals, institutions and companies that published advertisements in these media. Finally, we analyze to what extent some of the contents of those advertisements were related to broader discourses which took place in the 1940s (economic nationalism and defense of democracy), while others promoted values, beliefs, worldviews and lifestyles different from the culture the Communists were trying to spread.