In this text, we describe and analyze the radical political culture among left-wing student activists at the National University of San Marcos (UNMSM) during the 1980s, exposing the way in which student political cadres became involved and consolidated their position, as well as the limitations and critical scenarios that led to the end of the political culture they had built. Using a qualitative analysis methodology, we conducted fourteen semi-structured interviews with former student leaders at UNMSM. We found that the interviewees contributed to the reproduction of an infrastructure of epochal dissent whose cultural basis was a structure of class-based sentiment in its late phase.En este artículo describimos y analizamos la cultura política radical en la militancia de la izquierda estudiantil en la Universidad Nacional Mayor de San Marcos (UNMSM) durante la década de 1980, exponiendo la forma de producción del involucramiento y consolidación de los cuadros políticos estudiantiles, así como las limitantes y los escenarios críticos que conducen al fin de la cultura política que aquellos construyeron. Usando una metodología cualitativa de análisis, realizamos catorce entrevistas semiestructuradas a exdirigentes estudiantiles de la UNMSM. Evidenciamos que los entrevistados colaboraron con la reproducción de una infraestructura de disenso epocal cuya base cultural era una estructura de sentimiento de tipo clasista en su fase tardía.