This research aims to analyze the speech of President Jair Bolsonaro, on Instagram, about Covid-19, from the perspective of the post-truth. Thus, the article brings a debate about the discredit of science and the use of disinformation at an important moment, such as the coronavirus pandemic. The analysis brings as time frame the period of the beginning of the contamination in Brazil, which goes from March to April 2020. Through content analysis, the published content can be classified into 26 categories, which allowed to map the Bolsonaro’s predominant narratives on social networks, despite the opposition to scientific institutions