The radical aesthetic of the historical avant-garde movements has often been explained as a reaction to the catastrophic experience of the First World War and a denouncement of the bourgeoisie’s responsibility for its horrors. This article explores a blind spot in these familiar interpretations of the international avant-garde. Not only the violence of the World War but also the experience of a worldwide deadly pandemic, the Spanish flu, have moulded the literary and artistic production of the 1920s. In this paper, I explore this hypothesis through the example of Mário de Andrade’s famous book of poetry Pauliceia desvairada (1922), which I reinterpret in the light of historical studies on the Spanish flu in São Paulo. An in-depth examination of all parts of this important early opus of the Brazilian Modernism shows that Mário de Andrade’s poetic images of urban coexistence simultaneously aim at a radical renewal of language and at a melancholic coming to terms with a traumatic pandemic past