Police were called to Barnett Street in Kingswinford at around 4.20am on Wednesday, to reports of a 29-year-old man being found in distress.
Paramedics were then called at around 4.50am where they found the man in cardiac arrest. When they arrived, police were performing CPR on the man before ambulance staff took over.
He was taken to hospital to be treated for a head injury but confirmed dead a short time later.
West Midlands Police officers have now launched an investigation – and have sealed off the road as enquiries continue to try and establish what happened.
Anyone who was in the area at the time, or may have seen anything, is urged to contact police.
Detective Inspector Hannah Whitehouse, from West Midlands Police's homicide team, said: “A man has tragically died and it’s our duty to understand the circumstances of how this happened.
“Enquires are ongoing and as part of this we’re conducting a trawl of CCTV and speaking to potential witnesses.
“I’d ask anyone who knows anything or may have seen anything to contact us as soon as possible.”
A spokesman for West Midlands Ambulance Service said: "We were called at 4.48am on Wednesday to Barnett Lane, Kingswinford.
"An ambulance and paramedic officer arrived to find police performing CPR on a man in cardiac arrest.
"Ambulance staff took over resuscitation efforts and the man was conveyed on blue lights to Russells Hall Hospital where sadly he was confirmed dead a short time later."
Anyone with information can call West Midlands Police on 101, quoting incident number 483 of July 21.