California Governor Arnold Schwarzenegger has returned to work, disobeying instructions from doctors after he sustained minor injuries in a motorbike crash.

He vowed that the tumble would not stop him riding his beloved Harley Davidson.

Schwarzenegger needed 15 stitches in his upper lip following the Sunday afternoon incident in which a car backed out of a driveway in front of him. Schwarzenegger's son, Patrick, who was riding in the bike's sidecar, was unharmed. Both were wearing helmets.

"I was very lucky," Schwarzenegger said during an appearance Monday at a health centre for women and children in north Hollywood. "It could have been very different."

The former world-champion bodybuilder and action movie star kept to his regular work schedule even though he revealed that doctors had advised him to rest and avoid speaking for three days.

"My wife said, 'Make it seven'," Schwarzenegger joked.

He also said that the accident would not stop him from riding motorcycles, just as he had kept on riding during his acting career despite signing contracts forbidding him to do so.

"I did all those things anyway," Schwarzenegger said. "I never played by the rules."

Four years ago, Schwarzenegger broke several ribs and was hospitalised for four days after a serious motorcycle accident.