[From the Belle Époque to the city of vice: the fight against syphilis in Belém, Pará, 1921-1924].

This article analyzes the fight against syphilis in Belém, capital of the Brazilian state of Pará, between 1921 and 1924. When Instituto de Profilaxia e Doenças Venéreas (Institute for Prophylaxis and Venereal Diseases) was founded, headed by Dr. Heraclídes de Souza Araújo, many restrictions were imposed on prostitution in a bid to make prostitutes partners in the city's sanitation reform. The documents produced by the institute and published in newspapers of the day reveal the various clashes that occurred between doctors, the civil police force, and prostitutes, highlighting the prostitutes' attitudes to state intervention in their activities.