Lopez, blamed by President Nicolas Maduro for violent clashes that left three people dead last week, appeared at an anti-government rally in eastern Caracas and quickly surrendered to the National Guard after delivering a brief speech.
He was escorted to a National Guard vehicle amid a tumult among his followers and the media.
Lopez dropped out of public view after Maduro ordered his arrest on charges of homicide and inciting violence, but in a video message on Sunday, he invited his followers to join him in a march Tuesday at which he would turn himself in.
The Maduro government is grappling with angry student protests orchestrated by Lopez that began in the interior of the oil-rich country and boiled over last week in street clashes in Caracas that left three dead.
It's believed the violence flared when students at a university in the western state of Tachira staged a demonstration against rampant crime after a student was raped.
Maduro's regime has issued a warrant for his arrest, but Lopez -- who has been underground for the past several days -- emerged, undaunted, at Tuesday's demonstration to cheers of protesters.
Lopez issued a statement on Sunday, all but encouraging authorities to apprehend him at the demonstration.
"I have nothing to fear," he said. "I've done nothing wrong," he wrote, taunting the government on Twitter.
"If there is some decision to illegally jail me, I will be there to assume that persecution," he said.
His staunch opposition to the government dates back to the regime of late firebrand president Hugo Chavez, who in 2011 barred him from holding political office for three years.
His party, Voluntad Popular or People's Will party, has been front and center in leading the demonstrations that have roiled this oil-rich nation, which has been deeply divided in the aftermath of Chavez's death and the unsteady stewardship of the economy by Maduro.
The demonstrations have sprung up amid growing public discontent over rising crime and a worsening economy, despite having the world's biggest proven oil reserves.
Lopez and two other opposition leaders -- deputy Maria Corina Machado and the mayor of metropolitan Caracas, Antonio Ledezma -- advocate using street protests to force Maduro from office.
The strategy, which they dub "the exit," is controversial even within the opposition.
