After the country's top court ruled the gatherings could go ahead in the name of freedom of speech, Brazilian demonstrators held marches calling for marijuana to be legalized.
The demonstrations were held in 40 towns and cities late Saturday, according to Brazilian media.
Most were small affairs, with around 2,000 marching in the country's megapolis of Sao Paulo. Some people were seen smoking marijuana, but there were no immediate reports of arrests.
Possession and use of marijuana remains illegal in Brazil, and some commentators and social groups said they saw the marches as violating a law on justifying crimes.
But Brazil's Supreme Court last Wednesday ruled that the right to freedom of expression was more important and the marches could be held -- but that illicit drugs should not be consumed.
Last month, when protesters tried to hold a pro-marijuana rally in Sao Paulo without judicial support, the march degenerated into clashes with police who fired tear gas to disperse them.