The woman, who is 58, is in a stable condition in hospital after suffering head injuries on Sunday afternoon in Ballinderry, Co Antrim.
Police said they responded to a call from a member of the public reporting that a woman was “lying unconscious at premises at Old Road, Ballinderry”.
One line of enquiry is that it is a domestic related incident.
A 54-year-old man at the scene, who had injuries to the neck and chest, was taken to hospital for treatment.
He was later arrested under the Offences Against the Persons Act 1861 and taken into custody.
MIT detectives have 24 hours to either release or charge him.
Officers can make an application for an extension to his detention to a district judge or county court judge.