The demonstration, which according to organizers drew 90,000 people from key labor and employers federations, was held outside the state's legislative assembly a day after the federal government unveiled new measures to boost economic growth and aid key industries.
The demonstrators called for lower interest rates, lower taxes, action to bring down the value of the currency, the real, and to combat unfair foreign competition.
Similar protest demonstrations were held in the southern cities of Porto Alegre and Florianopolis last month.
"There is a global trade war and in war you have to take emergency measures," said Luiz Aubert Neto, president of the Brazilian Association of the Machinery and Equipment Industry, specifically calling for trade barriers.
"It's a demonstration in defense of Brazil's competitiveness," said Paulo Skaf, the president of the powerful Federation of Industries of Sao Paulo State (FIESP).
After it was announced last month that the economy last year grew a mere 2.7 percent and industry by only 1.6 percent, President Dilma Rousseff's government pledged new steps to boost growth.
Tuesday, Finance Minister Guido Mantega announced some fresh measures to help exporters, which complement a package of industry incentives launched by the government last August.
But Skaf said the relief measures announced by Mantega Tuesday were good but insufficient.
"It's a bit more of the same. They don't deal with the cause, just tackle the effects of the disease," he added, stressing the need for action to stop the appreciation of the real against the dollar, which is hurting the competitiveness of Brazilian products.
"If the more modern industries from Japan, China, South Korea or any other country were to move to Brazil, they too would suffer from the lack of conditions to be more competitive," Skaf noted.
Brazilian employers and workers are increasingly concerned at the poor performance of industry and its reduced contribution to the country's GDP.
Brazil, Latin America's dominant power and the world's sixth largest economy, has been blaming the real's appreciation on a "currency war" waged by advanced countries, which are flooding the market with dollars through cheap credit.
The foreign currency influx into countries such as Brazil, which offers high interest rates, lead to a stronger real and increased imports, and makes Brazil's exports more expensive.
Mantega Tuesday did not rule out new measures to curb the appreciation of the real against the dollar as well as steps to combat unfair foreign competition.
Clearly feeling the domestic pressure, Mantega on Wednesday underscored that bringing down the value of the real was a top priority for the government.
"We are not satisfied with the (current exchange) levels," he told Globo television.
Some analysts however warned that a lower real, currently trading at around 1.8271 to the dollar, would generate more inflation and might lead to unpopular salary cuts.
Among other steps announced Tuesday were government plans to buy national products up to 25 percent more expensive than imported ones in sectors such as construction machinery and medicines.
Mantega also detailed plans to bolster the information technology and communications sectors by purchasing computers for schools and extending broadband service across the country.
The auto industry will also receive fresh help while there will be an increase in government financing for industry and exporters.