A man was attacked by a gang of up to six men in Long Elms, Harrow Weald yesterday (Wednesday).
Two men were taken by London Ambulance to a north London hospital with non-life threatening injuries after the assault at 5.40am.
It is believed the incident was not a knife attack, but police have not confirmed whether a weapon was used during the attack.
Roads were closed for forensic officers to gather evidence, and three men have been arrested on suspicion of grievous bodily harm.
A 44-year-old neighbour, who did not wish to be named, said she heard men fighting in the street before police and paramedics arrived.
A cordon was put in place around the crime scene and Harrow CID officers are investigating.
