The group came to blows at about 7am at a Meriton Building site on Sexton Avenue in Castle Hill.

In the video, a large group of tradies in orange high vis can be seen struggling with another group in yellow high-vis.

At one point, one man hits another several times with his hard hat.

Some of the tradies tried to break up the fights, and more watched on from the sidelines.

Footage of the fight goes on for several minutes.

By the time police arrived, the group had mostly dispersed.

The fight appeared to take place outside a new-build apartment development by Meriton, which is for sale now off the plan as Castle Grange.

Paramedics were called to the scene and treated a 43-year-old man and a 55-year-old man.

Both were taken to Westmead Hospital with minor injuries.

Police have appealed for anyone with more footage of the fight or information to contact Castle Hill police station.