A baby girl is still fighting for life in hospital six days after an alleged assault north of Perth.

A 25-year-old man related to the baby faced court on Wednesday charged with aggravated grievous bodily harm and was released on bail.

The baby was rushed to Joondalup Health Campus with critical injuries before being transferred to Perth Children’s Hospital. 9News

Police allege the man shook the 11-month-old, leaving her with significant head injuries.

Paramedics were called to Two Rocks, about 55 kilometres north-west of Perth, about 8am on Thursday.

The baby was rushed to Joondalup Health Campus with critical injuries before being transferred to Perth Children’s Hospital.

She remained in the ICU there on Wednesday night.