It happened Monday night in the Rochdale section.
Police say the man and the child are both being treated by doctors at Jamaica Hospital because of this dog attack.
Witnesses say the animal sunk his teeth into the child and refused to let go.
Witnesses say the man and his 6-year-old son were walking on the sidewalk in Springfield Gardens.
The two were huddled under an umbrella carrying a kid's meal when all of a sudden a dog lunged at them.
"I saw a white figure go by. When I got closer to the window I noticed it was the dog and he got the little boy on the ground. And another young man was punching the dog trying to get him off him. And another white man was lying on top of him," said Dawn Johnson, a witness.
"I started screaming. I saw the baby on the floor, I saw the owner holding the dog trying to pull him off because the boy's foot was in the dog's mouth," said Sedriak Williams, a witness.
It happened at the corner of 151st Street and 140th Avenue around 5:30 Monday evening.
The child's sneakers, a leash, and the ripped open bags of food were all signs of the attack.
Witnesses say the pit bull mix was alone and that as the father tried to pry its teeth off the child's foot, the dog's owner came running around the corner to help.
"People need to be more cautious about their dogs and put them on the leash," Williams said.
Police say the man has minor injuries to his hands.
The boy has minor injuries to his legs.
No word on if charges will pressed against the dog's owner.