El trabajo analiza el uso de Twitter como canal de comunicación presidencialista en el periodo inicial de la COVID19. El objetivo es conocer el manejo de cuatro presidentes (España, Argentina, México y Brasil) y analizar la tesis del presidencialismo populista en líderes en su primera mitad de mandato. El método es cualitativo y compara los mensajes de la cuenta personal de Twitter las primeras 20 semanas de 2020. Se analizan en seis categorías: polarización, conspiración, exaltación y liderazgo carismático, personalización y vida privada, emoción y sentimientos, y publicidad en medios. Los cuatro presidentes comparten rasgos populistas, pero en distinto grado o caracterización. López Obrador y Bolsonaro ofrecen un perfil más populista con apelaciones emotivas al pueblo y su acción sanitaria salvífica. En cambio, Alberto Fernández y Pedro Sánchez responden al perfil de política pop, de liderazgo mediatizado para que la prensa amplifique sus logros. Se concluye que la pandemia ha acentuado el perfil presidencialista y personalista, aun cuando no encajen en el paradigma populista. Así, Sánchez y Bolsonaro sí despliegan una estrategia de comunicación de gestión sanitaria, mientras que López Obrador y Fernández apenas prestan atención a la política sanitaria This paper analyses the use of Twitter as a presidential communication channel during the first few months of the COVID-19 crisis. The aim is to determine how four recently elected presidents (those of Spain, Argentina, Mexico and Brazil) managed their political communication, and to explore the thesis that they resorted to populist messages during the first months of their terms in office. Using a qualitative methodology and the XL Node tool to capture data, a comparative analysis was performed on the messages posted on their personal Twitter accounts during the first 20 weeks of 2020, classified in six categories: polarization; conspiracy; exaltation and leadership; personalisation and privacy; emotions and feelings; and media publicity. The results indicate that the four presidents share populist traits, but to a different extent. López Obrador and Bolsonaro display a more populist profile, with emotional appeals to the people and to their saving action as regards the implementation of health policies. Conversely, Alberto Fernández and Pedro Sánchez are more akin to the pop politician profile, posting photographs and media messages with a view to receiving press coverage. Both post tweets, based on values and historical events, aimed at their grassroots supporters. The main conclusion is that the pandemic has enhanced the presidential and personalist profiles of the four leaders, although their actions during the COVID-19 crisis were not necessarily in keeping with the populist paradigm. Thus, Sánchez and Bolsonaro implemented a health management communication strategy, while López Obrador and Fernández paid scant attention to health policy.