Liljedahl was born in Stockholm, Sweden, and was discovered dancing with a Stockholm ballet company by director Joseph W. Sarno. At 17 years old, she began her film career with the lead role in Sarno's Inga (1968), which transformed her into an international sex symbol. Her other film roles included Sybil Vane in Dorian Gray (1970) and Eugenie in Eugenie... the Story of Her Journey Into Perversion (1970). In 1971, she appeared in the sequel to Inga, The Seduction of Inga, her last major role. She grew weary of the film industry and retired from acting at the age of 21.
A stage actress from age 10 and a member of the Swedish Royal Opera ballet at 12. Has also featured in Playboy magazine; 'The Girls of Scandinavia' (June 1968) and 'Flicker Flicka' (March 1969).