The man is thought to have been hit in the head with a brick, causing life-threatening injuries.
Three women and one man have been arrested on suspicion of violent disorder.
Shocked neighbours sent in pictures to SalfordOnline.com of the North West Air Ambulance trying to land in the middle of the residential area.
One eyewitness said: “I’ve never seen so many police in one place.”
Nine police cars, vans and three ambulances were called to Armitage Grove, near the Little Hulton Morrisons, at around 1.05pm today.
The victim is thought to have been discovered inside a house with a series of wounds to his face and head.
A road ambulance has now left the scene with a full police escort with flashing blue lights.
Anyone with any information is asked to call Greater Manchester Police on 101 or Crimestoppers, anonymously, on 0800 555 111.
