Police were called to Bodmin Crescent, Middleton, by the ambulance service shortly before 5am today (Wednesday).
Paramedics had received a report that a man had been found unconscious in the street.
The man was pronounced dead a short time later.
Police have cordoned off the street while they investigate how the man died.
A West Yorkshire Police spokesperson said: "At 4.56am today, police were contacted by the ambulance service who were attending a report of a man found unconscious in the street in Bodmin Crescent, Middleton.
"The man was pronounced dead at the scene a short time later.
"A scene remains in place and enquiries are ongoing to establish the circumstances."