Two men were injured in the fire on Halesowen Road, in Cradley Heath, at about 2.20am yesterday.
One of the men was found in a critical condition and taken to the Queen Elizabeth Hospital in Birmingham, while the other was treated for injuries not believed to be serious and taken to Russells Hall Hospital, West Midlands Ambulance Service said.
A man in his 40s who was taken to hospital with burns later died, police confirmed.
A spokesman for West Midlands Police said: "We were called following a fire at an address in Halesowen Road, Cradley Heath, in the early hours of yesterday morning.
"A man in his 40s was taken to hospital with burns but sadly later died. Our enquiries into the circumstances are continuing."
Jamie Arrowsmith, spokesman for West Midlands Ambulance Service, said: "We were called to reports of a property fire on Halesowen Road at 2.20am on Sunday morning.
"Two ambulances, a paramedic officer and a MERIT trauma doctor attended the scene.
"On arrival we discovered two patients, both men. One of whom was found in a critical condition. He received specialist trauma care at the scene before being taken to Queen Elizabeth Hospital, Birmingham.
"The second man was treated for injuries not believed to be serious before being taken to Russells Hall Hospital."
West Midlands Fire Service has been asked to comment.