Following 16 years as the Prosecutor of Oakland County, he was elected in 1992 to the office of County Executive. He was re-elected to a sixth term in 2012.
During his years as County Executive, Patterson has faced serious health problems, twice undergoing surgery to place stents to control blood flow and, in August 2012, being severely injured as the passenger in a car crash that left him hospitalized for a month and then placed in a medical facility for physical rehabilitation. Still in care as of October 2012, Patterson dismissed claims that his injuries left him unfit to serve if reelected.
In 2007, Patterson lost his son, Brooks Stuart Patterson, in a snow mobile accident and, later that year, lost his twin brother Stephen Patterson. In 2008, he established the Brooksie Way Half Marathon in honor of his son, an event sponsored by local businesses and drawing participants from the Oakland campus and area residents.