Police were called to Pennywell Road on Saturday morning following reports a man had collapsed.
"The man was taken to hospital but sadly later died as a result of his injuries. We are treating his death as unexplained," a  force spokesman said.
A post-mortem examination is due to take place later. Police have appealed for any witnesses to come forward or to call the 101 non-emergency number.
A man has died after being found with serious injuries in Bristol.