A cordon was placed around a road in Moulsecoomb after a suspected mortar shell was found in a garden there.
Sussex Police were called at about 3pm to Moulsecoomb Way.
The bomb squad arrived at about 7pm but left with the shell within about 15 minutes and the cordon was lifted.
A spokesman for Sussex Police said: “Just before 3pm on Wednesday (25 November) a small unexploded World War II mortar shell was found in the garden of a house in Moulsecoomb Way, Moulsecoomb, by contractors working there.
“Military EOD were consulted and some houses on either side were evacuated as a precaution, with a 50 metre cordon. EOD attended and just after 7pm they removed the shell and the cordon was lifted.”
Councillor Dan Yates, who represents Moulsecoomb and Bevendean on Brighton and Hove City Council, said: “It was found during gardening works and has been removed by the bomb squad. All back to normal now.”
Bus services were diverted for more than an hour and a half while the incident was dealt with.
Due to police activity in Moulsecoomb – Service 49 are not currently able to serve Shortgate Rd, Stonecross Rd, Bolney Rd, Halland Rd.
— B&H Buses (@BrightonHoveBus) November 25, 2015