The 44-year-old was found seriously injured on Westray Street, Milton, Glasgow at around 7.55pm on Thursday.
The emergency services attended and he was taken to hospital where he remains in a critical condition.
Police believe he was the victim of a targeted attack and are urging witnesses to come forward.
Senior Investigating Officer Detective Superintendent Raymond Brown said: “A man has sustained life threatening injuries as a result of this and we are appealing to members of the public to help trace those responsible.
“Inquiries are still at an early stage and we would ask anyone who may be able to assist with our investigation to come forward and speak to officers.
“The area of Westray Street is very residential and we are certain that there will be people who may have witnessed something that can help with our investigation.
“If you have any information, no matter how small, please get in contact will us as soon as possible.”
Chief Inspector Alan MacIntyre, Glasgow North area commander, said: “We believe this incident to be a targeted attack and I would like to reassure members of the community that there is no threat to the wider public."
Detectives have set up an online portal to encourage members of the public to submit information via https://mipp.police.uk/operation/SCOT21S26-PO1
Information can also be provided to police by calling 101 and quoting incident number 3276 of Thursday, 26 August, 2021. Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.