A dancer, Sherene Flash, had accused Amy Winehouse of hitting her in the eye after she asked to have her photo taken with the singer.
The incident took place last September, when the 25-year-old singer was part of the Trust Ball, organised by Prince Charles in London.
A judge declared that he was unable to say without a reasonable doubt that Winehouse deliberately hit Flash. He therefore could not find the singer guilty.
Winehouse denied ever meeting the plaintiff. However, in her testimony she said that she was only trying to move the woman out of her way. Winehouse added that she was afraid because of all of the photographers around her.
After the hearing, Winehouse returned to work on her next album.