The stabbing was reported at about 2:30 p.m. in the 1200 block of Sheldon Drive.
Arriving officers found a 20-year-old Oakley man suffering from multiple stab wounds. He was taken by helicopter to John Muir Medical Center in Walnut Creek where he is in stable condition today, police said.
The 17-year-old boy was found and arrested near his home in Oakley at about 4 p.m., according to police Sgt. Mark Misquez. He was booked into Juvenile Hall on suspicion of assault with a deadly weapon.
Police believe the stabbing was an isolated incident but the case remains under investigation. Anyone with information on the crime is asked to call Brentwood police Detective Folena at (925) 634-6911.