Mobile phone footage taken by a visitor to Marwell Zoo in Winchester showed the moment one of the Sulawesi macaques ran into a food shop.
Visitors took to social media to say they were locked inside shops while keepers tried to locate the pair at about 12:40 BST.
The monkeys were returned to their home within 30 minutes and no one was hurt.
Kevin O'Donnell posted on Twitter calling it a "great escape" and recorded one of the monkeys running around the zoo.
One visitor posted: "Monkeys have escaped at Marwell Zoo currently hiding out with the giraffes".
Another said Marwell staff acted "quickly and professionally".
A spokesperson for the zoo said guests and staff were asked to remain indoors while keepers dealt with the situation, which took about 30 minutes.
"We are grateful for the way in which our guests cooperated and thank them for their understanding," the spokesperson said.
"Our thanks to our animal management team who responded swiftly and carried out a model response.
"The two macaques have rejoined the rest of the family and all five will remain in the indoor part of their enclosure until a full investigation has been carried out.
"Our vet team has carried out checks and we are happy to report that the animals came to no harm. The zoo remains open as usual."
A zoo was put on lockdown after two adult monkeys escaped from their enclosure in Hampshire.