What Must Be Done (2009, based on a lecture delivered in 1997) has been translated into Portuguese as part of a pocket-book collection as O que deve ser feito (LVM Editora, 2019; translation by Paulo Pozonoff, preface by Rodrigo Saraiva Marinho). [Rothbard Institute version]
A previous translation by Fernando Fiori Chiocca was previously published in 2013, and is available here.