Emergency services were called to the discovery at the intersection of Watt St and Payton St in Raymond Terrace, north of Newcastle, about 5.45am on Saturday.
The roads back onto Irrawang Public School.
Local police have established a crime scene and the man is yet to be formally identified.
Anyone with information or who witnessed anything suspicious in the area is urged to contact Crime Stoppers on 1800 333 000.
Police will provide further information to the media later today as investigations continue.