Officers were called to Morpeth Street in the Netherthorpe area just after 12.30am today (Thursday March 24) following reports that a man had been stabbed.
The victim was taken to hospital where he currently remains in a serious but stable condition.
Temporary Detective Inspector Graham Stead, said: “I would like to reassure local residents that this incident is being treated as a priority.
“We will be reviewing CCTV footage of the surrounding areas and I would ask that anyone who has information about the incident to contact us.
“While I appreciate that this incident happened in the early hours of the morning, I would ask that anyone who was using the nearby petrol station or who was driving past the area and saw anything that could assist with the investigation to phone us on 101.”
Anyone with information is asked to quote incident number 21 of 24 March 2016. Information can also be passed anonymously to Crimestoppers on 0800 555111.