The Foreign & Commonwealth Office have recently updated their advice for people travelling to Brazil.
Firstly, your passport should be stamped with an entry stamp from the Brazilian immigration authorities upon arrival. This also applies when you arrive by land. If you do not have your passport stamped, you may be requested to pay a fine before departing.
It is also important that you retain your immigration landing card that is required to leave the country – if you lose it you could be subject to a fine.
In some instances you may also be required to pay an airport tax of R$65 if this has not been paid with your airline ticket.
Finally, and perhaps most importantly, if you have recently visited a country, which is known to suffer from outbreaks of Yellow Fever, you will need to show that you have been vaccinated against the disease.