The Spanish woman, named as Lucia C., works as an au pair on the Swiss Riviera, the area between Lausanne and Montreux on the shore of Lake Geneva.
She was last seen by friends on Friday night, reported Le Matin, but did not return home.
The car she was using – a grey Audi A3 – was found damaged at Monts-de Corsier north of Vevey on Saturday morning at around 6am, police said.
But so far, despite an extensive police search involving dogs, drones and helicopter, the young woman has not been found.
According to police Lucia is 163cm tall, of medium build, with brown eyes and light chestnut hair, wearing a blue top with a butterfly pattern, white trousers, gold-coloured shoes and a bronze watch.
Anyone with information about her whereabouts should contact Vaud police on 021 333 5333.