The workers were relocated after demonstrators attacked aid offices on Sunday in protest at the sacking of long-time governor Ismail Khan.
"All international and some national United Nations staff are being relocated to Kabul," said one UN official who did not want to be named.
"They are obviously relocated for security reasons."
He said 33 members of about 10 non-governmental organisations were also evacuated, with 61 workers pulled out in total.
The UN refugee agency has also suspended repatriations from nearby Iran.
Over 50 were injured in violence
in Herat on Sunday
Pakistan said it had relocated staff of its Consulate General in Afghanistan's Herat province to a new location after the violence.
"Our Consulate General and the staff members are safe," foreign ministry spokesman Masud Khan told a press briefing in the Pakistani capital Islamabad.
"We have temporarily relocated our staff," spokesman Khan said, adding that no damage was caused to the consulate's building.
Earlier, United Nations staff fled to bunkers as about 500 demonstrators ransacked buildings used by the UN High Commissioner for Refugees, the UN Assistance Mission in Afghanistan and three non-governmental groups.
Calm returned on Monday after a televised appeal by Khan and a government warning that any more violence would be met by military force - allowing the aid workers to survey the devastation.
"Oh my God, what have they done to our office?"
employee, International Organisation for Migration
"Oh my God, what have they done to our office?" said Abd Al-Karim, an employee of the non-governmental International Organisation for Migration whose premises were reduced to a smouldering ruin.
The European Union Special Representative for Afghanistan in a statement expressed dismay at the violent demonstrations and "wanton destruction" of property.
The EU urged religious, tribal and community leaders to use their influence "to quell the acts of violence and ensure the safety of the citizens of Herat and all international personnel working in the region".
Ismail Khan governed Herat city and province with an iron fist from 1992 apart from a five-year hiatus during the Taliban era. He has refused to take up a central government post offered by President Hamid Karzai.
His dismissal marks Karzai's latest effort, just weeks before presidential elections, to sideline the powerful regional commanders who control much of Afghanistan outside the capital Kabul.