A man has life-threatening injuries after a late night machete attack in Auckland.

Emergency services were called to a home on John Road in Stanmore Bay about 10.30 last night.

They arrived to find a 31-year-old man had been hit in the head with a machete.

He's in a critical condition in Auckland Hospital, with deep lacerations to his face, left chest and back.

Police say another man is assisting them with their inquiries.