A crime scene has been declared after a man suffered serious stab wounds at a home north of Brisbane.

Police were called to an address on Young Street, Petrie, about 11am on Saturday after reports a man in his 20s had a stab wound to his back.

The man was soon transported to Royal Brisbane and Women's Hospital from a separate address in nearby Kallangur.

He remains in a critical but stable condition. A 22-year-old man is assisting police with their enquiries.

Anyone with information should call Policelink on 13 14 44 or Crime Stoppers on 1800 333 000.