The protesters blocked portions of the two large avenues in the Argentine capital as they made their way to the embassy, according to local media.
Protesters carried banners with the names of Argentine leftist organizations and chanted outside the embassy's security perimeter.
Pressure is growing on Maduro to step down after more than a dozen European Union nations on Monday joined the United States, Canada and a group of Latin American countries in recognizing opposition leader Juan Guaido as Venezuela's legitimate leader.
However Russia, China and Turkey continue to back Maduro, accusing Western nations of meddling.