Casino games are prohibited in Brazil. Poker, either land-based or online, is unregulated in Brazil as it is considered a game of skill and, therefore, falls outside of the scope of Decree-Law No. 3,688/1941 (the Misdemeanour Criminal Act of 1941  MCA). No specific regulation applies.
Yes, believe it or not, Brazil has become one of the premier poker-playing countries in the world, especially for online gamblers. Brazilian authorities don't regulate online gambling in the country. As a result, Brazilian gamblers have the freedom to choose from thousands of online poker rooms.