Three of the robberies happened along the Delaware River Path last week. The four others happened a short distance away on West Trenton Avenue.
Those are the latest in a string of robberies over the past month. In one of the incidents, the victim was pistol-whipped.
According to investigators, at least two people take part in each robbery.
At least once, they drove away in a dark-colored Honda.
Anyone with information is asked to call Morrisville Police.