The rescue operation was launched just after 6pm on Tuesday evening after police received information that a woman was swimming in the Rhône near the Butin bridge, newspaper 24 Heures reported.
Since it was dark and the temperature hovered around 10 degrees, rescuers “feared the worst”, Frédéric Jaques, head of Geneva's fire and rescue service (SIS), told the paper.
But the naked bather obviously wasn't concerned as she seemed to play a game of cat and mouse with her would-be saviours, said 24 Heures.
She was spotted in the river near Jonction but then climbed out on to the bank and disappeared, eluding the helicopter, patrol cars and boats that were scouring the area.
The operation was abandoned at 6.30pm, with police and SIS officers calling the woman “irresponsible” for her actions, said the paper.