She was the first Soviet soprano to be trained at the studio of La Scala in Milan, and her Italian repertoire included Verdi's Leonora in Il trovatore, Elisabetta in Don Carlo and Aida, and Puccini's Tosca.

[1] In her final year of studies, Milashkina became a member of the Bolshoi Opera in 1958,[1] making her official debut as Tatyana in Tchaikovsky's Eugene Onegin;[2][7] she remained one of the leading sopranos until 1989.

[4] Her Russian repertoire also included Yaroslavna in Borodin's Prince Igor, the Tsarina in Rimsky-Korsakov's The Tale of Tsar Saltan, Natasha in Prokofief's War and Peace, and Maria in Tchaikovsky's Mazeppa.

[8] In Bolshoi productions, she performed there also in 1964 as both Lisa in Pique Dame and Natasha in War and Peace, alongside Juri Mazurok as Prince Bolkonsky, and Alexander Vedernikov as General Kutusov.

[12] The New York Times music critic Harold C. Schonberg summarised the effect of this performance of Onegin, writing that "[there] was the special kind of authenticity that only Russians can supply in this singularly beautiful opera".

"[13] In a 1983 portrait for the Bolshoi Theatre, E. Grosheva wrote: Milashkina's voice is unique; nature and intelligent labour generously endowed it with freedom and richness of colours, fullness and roundness of sound – ringing, flying in the upper notes, substantial, chesty in the lows, equally collected and expressive in the whole range, covering about two and a half octaves.

[6] A reviewer from the French newspaper Aurore noted in 1978, when the Bolshoi Theatre toured to Paris: "She slightly resembles Victoria de Los Angeles, but her voice is much more luxurious, warmer, more reverent".

[18] In 1974 she recorded her most famous role, Lisa in The Queen of Spades (Pique Dame), opposite Atlantov, with Bolshoi forces conducted by Mark Ermler.

[20] Milashkina took part in a 1979 Bolshoi DVD production of Dargomyzhsky's The Stone Guest conducted by Ermler, as Donna Anna alongside Atlantov as Don Juan and Alexander Vedernikov as Leporello.

[26] She appeared as Lisa again in a 1983 DVD recording of Pique Dame from the Bolshoi, conducted by Simonov, with Mazurok, Atlantov and Elena Obraztsova as the Old Countess.