She started the first lesbian organisaton in Slovenia, LL (Lesbian Lilit), in 1987. Before that she had cooperated with Magnus, a mostly gay male Slovenian organisation, and Lilit, a feminist group, from which LL evolved.

Most important among Tratnik's projects and achievements are co-editing the Sloenian gay and lesbian magazine Revolver and editing the lesbian bulletin Pandora. She has written L, the anthology of the Slovenian lesbian movement, and organised an international lesbian camp on Rab island (now in Criatia) and a week of lesbian film.

She also contributed significantly to increasing the visibility of lesbians and changing society's attitude towards homosexuality by her public appearances and work with the media. In 1998 Tratnik published her first novel, Pod niclo (Below Zero).