Police said they responded to the accident about 10:15 p.m. Wednesday.
They said 30-year-old Lynn Pickard of Winchester was traveling south on Fullam Pond Road when she lost control of the car and hit the tree.
Police said 34-year-old Terry Pickard of Winchester died.
Lynn Pickard was taken to Dartmouth Hitchcock Medical Center with serious injuries.
Police are investigating the accident.