The 21-year-old admits she was scared by the stunts she performed for Snow White and The Huntsman.
The adaptation is a darker twist on the classic fairytale, and Stewart says she had to overcome her fear of horses in order to film some of the film's action scenes.
'I got to jump off cliffs and ride horses, and that terrifies me,' she said at WonderCon.
'I was really, really not happy about having to do all that [horseback riding],' she confessed. 'I don't like that - I hate that.
'I fell off a horse once and hurt myself really badly,' explained the star. 'I broke and dislocated my elbow when I was, like, 9.'
Snow White and the Huntsman, also starring Chris Hemsworth and Charlize Theron, hits cinemas nationwide on June 1st.