Around 3.15pm on Tuesday afternoon, the 18 year-old man was seriously assaulted by two men in Princes Street, Port Glasgow.
Police and ambulance attended and the injured man was taken by ambulance to Inverclyde Royal Hospital where he is being treated for stab wounds. Hospital staff describe his condition as stable.
Detective Sergeant Neil Martin said: "We are treating this incident as a targeted attack on this 18 year-old, and we are following a positive line of enquiry, however we are appealing for any witnesses to come forward to police. This is a very busy area and any witnesses, or any drivers who were in the area with dash-cam are asked to contact us as they may have information that is vital to our inquiry.
"There are additional police patrols in the area to provide public reassurance, and anyone with concerns should speak to officers."
Anyone with information should contact Greenock Police Office through 101 quoting reference number 2246. Alternatively Crimestoppers can be contacted on 0800 555 111, where anonymity can be maintained.