Hundreds of thousands of demonstrators took part in rival marches in the Venezuelan capital, Caracas.
Anti-government protesters called for President Nicolas Maduro’s removal.
Opposition blames Nicolas Maduro for the country’s economic crisis and accuse the electoral commission of delaying a referendum that could shorten his stay in power.
The president, whose supporters also rallied in huge numbers, accused the opposition of trying to stage a coup.
Nicolas Maduro said at a rally in central Caracas: “The nation has triumphed. They wanted to intimidate the people but the people are here.
“We have defeated an attempted coup that tried to fill Venezuela and Caracas with violence, death.”
Opposition leaders said their protest had gathered at least their anticipated one million people.
Opposition politician Jesus Torrealba said: “We have shown to the world the importance of Venezuela and how much it wants change.”
Protesters said they had enough of the policies of the governing United Socialist Party of Venezuela.
A small group of protesters clashed with riot police as the peaceful rally ended.
In the run-up to the march, a number of opposition politicians were detained.
The opposition hopes the march will pressure the electoral authorities into allowing them to launch the second petition needed to trigger Nicolas Maduro’s recall referendum as soon as possible.