The activists protested Monday on the steps of the Franklin Institute in central Philadelphia as Romney spoke inside at an event organized by the Independence Hall Tea Party.
The protesters said that when they tried to go inside, they were refused entry. Event organizers eventually granted them refunds for their $20 tickets after they chanted loudly on the steps.
The activists, who were from groups such as Occupy Philly and Fight For Philly, said they just wanted to ask Romney questions about his policies.
Che Saitta, 23, from Philadelphia, who said she was with Fight For Philly, said she was among those denied entrance.
"I don't know why. They wouldn't tell me," she said.
Saitta, who said she graduated from Temple University last year with a degree in graphic design but is working four jobs in unrelated fields to make ends meet, said she wanted to ask Romney about his stances on health care insurance and student loans.
Paola Pedraza-Rivera, 22, from Philadelphia, said when she got up to the entrance she saw her name highlighted on a list and was denied entry.
"They just said 'You can't come in, period,'" said Pedraza-Rivera, who said she wanted to tell Romney to close tax loopholes and fund education and social programs instead.
A message could not be left for a number listed on the Tea Party group's website.