Este documento reconstruye la huelga de los trabajadores de Cementos El Cairo y la masacre de Santa Bárbara, Antioquia, ocurrida el 23 de febrero de 1963, donde fueron asesinados por balas oficiales los obreros de Cementos El Cairo Pastor Cardona, Rafael Antonio González, Luis Ángel Holguín; el obrero de Cementos Argos Luis Ángel Ruiz Villada; los campesinos Rubén de Jesús Pérez Arango, Joaquín Emilio Román Vélez y Luis Esteban Serna Villada; los vecinos de Santa Bárbara Jesús Román, José de Jesús Suaza, Juan María Holguín Henao, e Israel Antonio Vélez Díaz; y la niña María Edilma Zapata de 10 años, estudiante de la escuela maría Auxiliadora e hija del obrero y sindicalista Luis Eduardo Zapata. / Abstract. This article reconstructs the main aspects of the Santa Barbara Massacre that occurred in Antioch on the 23rd of February in 1963. By analyzing in the firs place the establishment of the civil dictatorship of the Frente Nacional and the economical recession taking place during the first years of the 1960 decade that distinguished the relationship between the conservative government of de Guillermo León Valencia with that of the working class. In addition, this article studies the characteristics of the labor policies of the Frente Nacional and the historical reconstruction of the facts behind the worker’s strike of the Cementos El Cairo Company. Ultimately ending with the tragic events of the Santa Barbara Massacre.