International flights from South & North America to Brazil have a luggage limit of 40kg/88lb per person with TAM, with similar limits for other international carriers that cover Brazilian air routes. Many European, African and Asian airlines limit luggage to 32kg/70lb.
Domestic flights in Brazil with TAM and GOL, the two major internal carriers, have luggage limits of 23kg/50lbs per person. This is made up of two bags maximum. If flying in with TAM, any connecting domestic flights have Hand luggage is limited to 5kg/11lbs per person, with a size of 10x10x20cm.
Most business visitors and tourists can manage to pack less than this, although cruise passengers touring Brazil after finishing in Santos/Sao Paulo or Rio de Janeiro quite often exceed those limits (due to needing more outfits of course!). Excess charges depend on the class of airline seat bought. The smaller airlines such as Avianca, WebJet, Trip, Azul and JetSul also have a general limit of 23kg on inter-city flights, but this may be lower on some of the more local flights with smaller planes. Check your tickets before every flight to make sure, they should state the limits, or Baggagem.
In practice, airlines do not always charge for baggage that exceeds 23kg. If the flight is not full, you may be lucky and find your luggage being passed through without a word, just a smile in return. If you arrive with excess luggage, then a friendly smile and perhaps even a little flirting may help, as long as it is directed at the correct person - it has been known to work in the past!
Of course, many visitors to Brazil will be thinking of bringing oversize items with them - surf boards, kite-surf and scuba-diving equipment, instruments, golf clubs, triathlon bikes even. These will be charged extra, and it is necessary to check with the airline for details in advance.