Today, at around 1am, a 27-year-old man was leaning against a wall in front of a hotel on Soldier Street, Castle Hill, when two other men confronted him.
After a brief verbal quarrel, the two men would have pushed him back, which would have given him a violent impact on the wall.
They left the scene and were taken to Westmead Hospital by ambulance.
He received treatment for skull fractures, bleeding to the brain and internal injuries. But now in a stable state.
After questioning officers from the Hills Police District Command, two men aged 18 and 19 were arrested this afternoon and taken to the Penrith Police Station.
Both men were charged with aggravated bodily harm and were released on bail in the Penrith Local Court on February 5, 2019.