The "massive" marsupial can then be seen punching Mitchell in the face and kicking him to the ground before quickly hopping away.
Family friend Tina Grace Rowe said you could see the animal was going to go for him.
"It was just staring at him and he picked up something to try and shoo it away and as soon as he did that you could just see that it was going to go at him," Rowe told 7 News.
"He was massive. He was a big male kangaroo – big chest."
The dad did not suffer any serious injuries.
It comes as locals of South West Rocks say kangaroos are becoming a problem in the area as more of them trek into town in search of food with the bush fire crisis having destroyed their habitat.
NSW Environment and Heritage advises anyone who feels threatened by a kangaroo, to move well clear.
"Try not to attract the kangaroo's attention and keep your head and arms low," it states on its site.
"If you need to, carefully retreat in a crouched or crawling position to a safe location or distance away. If you can, position an object such as a tree or fence between you and the
kangaroo and call for help.
"If you are attacked, drop to the ground and curl into a ball with your hands protecting your face and throat. Try to remain calm and still until the animal moves away, or if you can, keep low to the ground and move behind some form of cover."
