The 31-year-old was assaulted in Dumbryden Grove, in the Wester Hailes area of Edinburgh, at around 4.30pm yesterday.
He sustained a serious, life threatening injury and remains in a critical condition at Edinburgh Royal infirmary.
Police are appealing for anyone who may have witnessed, or have information, about this serious assault to come forward.
A police spokesman said: "The 31-year-old victim is fighting for life in hospital following this serious assault and we are keen to hear from anyone who has information and can assist us with this investigation.
"Anyone who believes they have information is urged to contact police immediately on 101."
Chief Inspector Mark Rennie said: "I'd like to reassure residents that at this stage this appears to be an isolated incident.
"A detailed investigation has been ongoing since it happened and we will have officers in the area throughout the weekend to reassure the local residents and carry out further enquiries."