The three states in the temperate South: Paran , Rio Grande do Sul, and Santa Catarina-cover 577,214 square kilometres (222,864 sq mi), or 6.8% of the national territory. The population of the South in 1991 was 23.1 million, or 14% of the country's total. The region is almost as densely settled as the Southeast, but the population is more concentrated along the coast. The major cities are Curitiba and Porto Alegre. The inhabitants of the South enjoy relatively high living standards. Because of its industry and agriculture, Paran  had the highest average income in 1994, US$ 3,674, while Santa Catarina, a land of small farmers and small industries, had slightly less, US$ 3,405.

In addition to the Atlantic Forest and Araucaria moist forests, much of which were cleared in the post-World War II period, the southernmost portion of Brazil contains the Uruguayan savannah, which extends into Argentina and Uruguay. In 1982, 83.5% of the region had been altered by anthropic activity, with the highest level (89.7%) in Rio Grande do Sul, and the lowest (66.7%) in Santa Catarina. Agriculture--much of which, such as rice production, is carried out by small farmers-has high levels of productivity. There are also some important industries.
The Southeast consists of the four states of Esp¡rito Santo, Minas Gerais, Rio de Janeiro, and São Paulo. Its total area of 927,286 square kilometres (358,027 sq mi) corresponds to 10.9% of the national territory. The region has the largest share of the country's population, 63 million in 1991, or 39% of the national total, primarily as a result of internal migration since the mid-nineteenth century until the 1980s. In addition to a dense urban network, it contains the megacities of SÆo Paulo and Rio de Janeiro, which in 1991 had 18.7 million and 11.7 million inhabitants in their metropolitan areas, respectively. The region combines the highest living standards in Brazil with pockets of urban poverty. In 1994 São Paulo boasted an average income of US$ 4,666, while Minas Gerais reported only US$ 2,833.

Originally, the principal biome in the Southeast was the Atlantic Forest, but by 1990 less than 10% of the original forest cover remained as a result of clearing for farming, ranching, and charcoal making. Anthropic activity had altered 79.5% of the region, ranging from 75% in Minas Gerais to 91.1% in Esp¡rito Santo. The region has most of Brazil's industrial production. The state of São Paulo alone accounts for half of the country's industries. Agriculture, also very strong, has diversified and now uses modern technology.