The 42-year-old 'Trainspotting' star was out riding on his motorbike when a car collided with the vehicle, sending him sprawling onto the road, reported Contactmusic.
McGregor took to Twitter after the incident to urge motorists to keep a lookout for bikers.
"Check your mirrors for bikers before you change lanes people. It's annoying when picking yourself off the tarmac to hear 'didn't see you'.
"Very kind. I'm wasn't (sic) knocked down but bumped into. Just keep your eyes in your mirrors. Bikers are vulnerable. And very cool," McGregor said.
McGregor broke his leg in a crash in London in 2007 and totalled a bike when he skidded off a road in Scotland in 2000.