Machado went into hiding shortly after the July 28 vote, when the security forces began cracking down on protests against Maduro’s claim of victory.
She had urged opposition supporters to turn out in their “millions” but the crowds on Thursday were smaller than those in the direct aftermath of Maduro’s alleged power grab.
Thousands of ruling party loyalists held their own rival demonstrations in central Caracas on Thursday, showing the government retains the strong support of some.
Maduro has accused the United States — long opposed to his rule — of plotting to overthrow him.
The Venezuelan leader, who counts on the backing of Russia and Cuba, the military, courts and electoral commission, has claimed that a senior FBI official was among a group of seven “mercenaries” arrested this week.
The US State Department denied US involvement in any coup plot.
Maduro has ruled Venezuela since 2013 and despite a sustained economic crisis that has pushed seven million citizens to emigrate, has shown no signs of relinquishing power.
Ahead of Thursday’s protests, several activists and opposition figures, including a politician who ran against Maduro in July, were reportedly arrested.
With neither the charisma nor the flush oil revenues of his mentor Chavez, Maduro is accused of relying on brute force to hold on to power and of driving the economy into the ground.
