Emergency services descended on Dundee’s City Quay on Monday night after fears were raised over a woman walking on the Tay Road Bridge.
The search and rescue helicopter from Prestwick was called in to help with the search, which also involved dozens of police, firefighters and the coastguard.
Officers used flash lights and flares to light up the water after receiving a report about the woman from a concerned motorist just before 10pm.
The motorist had reportedly been travelling from Dundee towards Fife when he spotted the woman and became concerned, before coming back across the bridge and being unable to locate her.
Scores of residents also made their way out of their waterfront flats to help.
James Edgar said: “I saw the police and fire engine turn up when their lights started flashing through my window. I was just watching TV with my girlfriend. Once I found out what had happened I wanted to help as much as I could.”
Officers closed the bridge for around half-an-hour to assist with the search.
A police spokesman said: “The lady is described as being in her 20s with dark hair and wearing a bright purple top.
“A joint search operation involving the police, coastguard and Ffre service was carried out last night but failed to trace anybody matching the description.
“Anybody with any information regarding this incident is asked to contact Police Scotland in Dundee by calling 101.”