The victim's body was found at Hedderley Walk, near St Ann's Well Road, in the St Ann's area just after 16:00 BST on Sunday.
Several roads in the area were sealed off and officers carried out extra patrols of the area.
The victim was a 43-year-old man but no further details have yet been released. Police have appealed for any witnesses to come forward.
A murder inquiry has been launched in Nottingham after the death of a man.