Jose Miguel Vivanco, the group's longtime Americas director, was expelled along with the group's deputy director Daniel Wilkinson for engaging in political acts while in the country on a tourist visa, the government said.
"We aren't going to tolerate any foreigner coming here to try to sully the dignity" of Venezuela, Foreign Minister Nicolas Maduro declared. Vivanco is Chilean and Wilkinson is a U.S. citizen.
Kenneth Roth, executive director of Human Rights Watch, called the expulsion "further evidence of Venezuela's descent into intolerance."
"Chavez may have kicked out the messenger, but he has only reinforced the message - civil liberties in Venezuela are under attack," Roth said in a statement Friday.
The rights monitors were handed a letter Thursday night accusing them of "anti-state activities." Then their cell phones were seized and their requests to contact their embassies were denied, the group said.
Venezuelan state television showed them gathering their belongings and being driven to the airport in a caravan complete with motorcycle escorts and flashing lights. They arrived in Sao Paulo, Brazil, on Friday morning.
Their report, "A Decade Under Chavez: Political Intolerance and Lost Opportunities for Advancing Human Rights in Venezuela," delivered hours earlier at a news conference in Caracas, said Chavez's government has "tolerated, encouraged, and engaged in wide-ranging acts of discrimination" against opponents and that Chavez has sometimes "openly endorsed acts of discrimination."
Chavez had threatened to expel any foreigner who comes to "slander" his government; this was the first time he did so.
Venezuelan Information Minister Andres Izarra on Friday called Human Rights Watch a "front organization" serving U.S. interests. Maduro also accused Vivanco and Wilkinson of acting at the behest of the U.S. government and of receiving U.S. funding.
Human Rights Watch, however, says it accepts no government funds, directly or indirectly.
And Vivanco has criticized governments of all stripes - for example, he is a harsh critic of what he considers a conscious effort by Colombian President Alvaro Uribe, a close U.S. ally, to suppress investigations of links between his political supporters and right-wing death squads.
Vivanco, for his part, told reporters before his expulsion that Chavez's government has "weakened democratic institutions and human rights guarantees" while trying to sideline the opposition and consolidate power.
By Associated Press Writer Jorge Rueda