The two actors starred in the 1988 film as unlikely twin brothers who were separated at birth.
Work is about to start on a sequel, called Triplets, with Eddie Murphy playing a long-lost third sibling, and Schwarzenegger has now revealed they were initially paid nothing to appear in the original.
He tells Britain's Daily Mirror newspaper, "I said right off, 'Don't give me anything, you are taking a risk, let's make the movie for $16.5 million, let's keep it cheap, no one takes a salary. Let's just get a certain percentage, the back end, and then we'll split that.'"
The gamble paid off and Twins went on to gross $216 million at the worldwide box office, making a lot of money for the two lead actors.
Schwarzenegger adds, "In the end, we made more money than we ever made on anything else we've done."