While best known for her accomplishments in Czech music, particularly that of Dvorák and Smetana, Benackova has performed in nearly all the lirico-spinto soprano roles in the Italian repertoire. She has earned equal praise for her musicianship and vocal beauty, though she is occasionally accused of bringing a non-Italianate coolness to those roles. She has also sung the more lyric Wagner roles, including Eva and Senta.
Her opera debut was at the National Theater in Prague, as Natasha in Prokofiev's War and Peace, in 1970. In 1975, she sang her first Jenufa there; like Dvorák's Rusalka, that role has since become one of her signatures. Jenufa was also the vehicle for her 1978 Vienna State Opera debut. In 1979, she made her Covent Garden debut as Tatyana in Tchaikovsky's Eugene Onegin. She sang the title role of Smetana's Libuse for the re-opening of the National Theater in Prague in 1983. Her Met debut was as Kát'a Kabanová in 1991, which she also recorded with Sir Charles Mackerras in 1997. She also continued her career as a concert artist in works by Dvorák, Janácek, and Mahler. Benackova has been involved in the restoration of Gustav Mahler's birthplace at Kaliste in the Czech Republic.