The musician said that at one point he feared his commitment to the anti-poverty cause might force him out of the band.
"They are hugely supportive spiritually and financially of the work I do, but they are in a rock 'n 'roll band, and the first job of a rock 'n 'roll band is not to be dull," Bono told British Broadcasting Corp. radio.
"So we have to be very careful about just letting me go too far."
With fellow musician Bob Geldof, Bono was one of the leaders of this year's international Make Poverty History campaign and Live 8 concert, and frequently makes onstage statements about global poverty during U2 concerts.
Bono acknowledged that his campaigning had sometimes "raised eyebrows" among his fellow band members.
"When I do my rant on making poverty history, I have got Larry Mullen, our drummer, behind me looking at his watch, timing me," he said.
"There was one point when I thought, 'I'm going to be thrown out of the band for this stuff.'"
But Bono said he now feels the other band members recognize that U2's audience appreciates what he is doing.
"I thought we would wear our audience out, but it hasn't happened," he said. "People are smart out there. They know what you are doing, they know the compromises you are making, they get it."
Edit: Oops... someone posted it below. Now behind a cut so that people don't get annoyed by having to scroll through. :)