Sandmoor Drive in Alwoodley, Leeds was closed after a workman found a suspected WW2 hand grenade which fell down from a loft while it was being cleared out.
The grenade was thought to have been brought back by a previous owner, and was rusted but appeared to be in line with a Second World War device.
A military bomb disposal unit was called to the scene at about 6.30pm and the weapon was disposed of.
The road has just been reopened, West Yorkshire Police confirmed.
No-one was injured during the incident.