The 74-year-old man was struck as he walked home past an AMCO construction site in Edinburgh's Newcraighall Road at 2pm yesterday.
He was taken to the Royal Infirmary of Edinburgh with serious injuries to his legs and torso. He remains in a serious condition.
Police have appealed for witnesses to the accident.
Sergeant Brian Smith said: "The elderly male has sustained some serious injuries as a result of this collision and we are now keen to speak with anyone who was in the area at the time.
"Motorists, pedestrians and other members of the public who witnessed the incident, or who have information relevant to this investigation, are asked to contact police immediately."
Anyone with information can contact Police Scotland on 101 or Crimestoppers on 0800 555 111.