Officers were called to an address in Mount Street, Sharrow, at around 10.15pm last night.
They found the body a 40-year-old man outside.
A South Yorkshire Police spokeswoman today said it was believed the man had fallen from the top floor of a block of maisonettes.
A 38-year-old woman was arrested at the address on suspicion of murder.
Anyone with information is asked to call 101, quoting incident 1303 of 12 October, or Crimestoppers anonymously on 0800 555 111.