It happened near the village of Huwara - which has been the scene of previous deadly attacks on Israelis and rampages by Jewish settlers in retribution.
The shooting took place at a carwash.
The gunman is said to have approached on foot and opened fire with a handgun.
The Israeli ambulance service said the two men aged 28 and 60 were pronounced dead at the scene. Both are said to have been civilians from Ashdod in southern Israel.
Israeli media reported that they had come to the West Bank to fix their car and spent several hours in Huwara.
