A man who allegedly set fire to a woman in Medina, near Kwinana, on Sunday afternoon will face court on Monday.
Police charged the man after the incident that happened in Medina.
Officers will allege the 37-year-old doused the woman and part of a lounge room in petrol before setting both alight.
The woman, who is in her 20s, ran from the house, and neighbours put out the flames and called emergency services.
She was taken to Fiona Stanley Hospital with burns to 35 per cent of her body.
The man, who was also taken to hospital with burns, has been charged with grievous bodily harm and criminal damage by fire. He will face court via a bedside hearing.