Do Brazil passport holders need a visa to visit BO?

No visa required. Brazilian ordinary passport holders enter Bolivia visa-free for tourism for up to 90 days per calendar year under the Mercosur freedom-of-movement framework, and may even travel on a valid national ID card instead of a passport. Brazil and Bolivia are both full members of Mercosur, so Brazilian citizens enjoy visa-free entry to Bolivia for tourism and short visits. The standard tourist permit is up to 90 days per calendar year, granted free of charge at the port of entry. Because of the Mercosur regional agreement, Brazilians may cross using either a valid passport or a valid Brazilian national/state identity card (RG/CIN) that is in good condition and not expired. No advance application, eVisa, or visa-on-arrival fee applies. Travelers should still carry proof of onward/return travel and accommodation. A key practical point: because Brazil is classified as a yellow-fever risk country, Bolivian authorities can ask arrivals coming from Brazil for an International Certificate of Vaccination (yellow fever), particularly when visiting lowland eastern regions (Santa Cruz, Beni, Pando, etc.). Bolivia is in South America and is not part of the Schengen area, so Schengen 90/180 and ETIAS rules do not apply.