It happened around 7 p.m. on the 4600 block of Newportville Road in Bristol Township.
Family members told police the 28-year-old man had been working under his vehicle in his driveway, making repairs, when the jack failed and the vehicle fell on top of him.
Newportville Fire Rescue, Levittown 2 Fire Rescue, Parkland Fire Rescue and Bucks County Rescue Squad responded.
They removed the victim from under the vehicle, but were unable to revive him.
The man was pronounced dead at the scene.
His identity has not been released at this time.