Both lenders and borrowers told mortgage brokers how unwelcome they were.
The protesters gathered outside of the Moscone Center in San Francisco and chanted "jail time for corporate hacks."
Members of the activist group Answer Coatlition were among the protesters.
Attendees said they had never seen anything like it at past conventions.
However, this one comes in the midst of a housing criss which has lead to the nation's economic meltdown, and a bailout of some private banks, which has drawn heavy, sharp criticism from people throughout the country.
Some of the brokers said the last thing they ever wanted to see was people losing their homes and that much of their convention is focused on steering people away from foreclosure.
The protesters said they felt it was obvious that the bailout plan enacted by the government merely rewards those responsible for the economic mess.
"This is criminal and a lot of the people inside here are criminal too," said Richard Beker of the Answer Coalition. "They are responsible for fraudulent loans."
"Let's face it," said Cheryl Crispen of the Mortgage Bankers Association. "Nobody benefits from foreclosure -- the borrower, the homeowner, the community or the lender."
Monday's sessions featured seminars like "Coping, Controlling and Capitalizing" and "How Congress is Responding to the Mortgage Industry."
One attendee said this is the first time she has ever seen people take this much interest in an industry that many call boring.