West Yorkshire Police were called at 4.21am by the ambulance service to a report of a man with stabbing wounds to his neck.
The 38-year-old victim was then taken to hospital where he remains in a serious but stable condition.
A spokesman for West Yorkshire Police said: "Police are appealing for witnesses following a stabbing in Birkby in the early hours of this morning (05/10).
"Officers were called at 4.21am by the ambulance service to a report of a man with a stab wound to his neck.
"The victim, a 38-year-old, was taken to hospital where he remains in a serious but stable condition.
"Enquiries are ongoing."
Detective Inspector Steph Fox, of Kirklees CID, said: “I would appeal for anyone with information on this incident to contact police.
“Thankfully the victim’s injuries aren't life threatening but it could have quite easily been a different story.
“Our investigation is at an early stage and we are pursuing a number of active lines of enquiry.
“I would appeal for anyone with information or anyone who saw anyone hanging around in the Willow Lane area in the early hours of this morning to contact police.”
Anyone with information is asked to contact Kirklees CID on 101, quoting crime reference 13190510889. Information can also be passed anonymously to independent charity Crimestoppers on 0800 555 111.