Terekhova's acting debut was in 1965 in the film Hello, That's Me!. Margarita became particularly popular in the late 1970s, after the release of a costumed musical TV films The Dog in the Manger and D'Artagnan and Three Musketeers. At first she played the capricious Countess Diana de Belflor, in the second - the treacherous Milady. Leading roles followed in films made by Directors including Andrei Smirnov and Ilya Averbakh (Monologue, 1972) as well as the dual-role in Andrei Tarkovsky's acclaimed Mirror (1975). And more international co-productions came after, including George Cukor's The Blue Bird (1976) and Konrad Wolf's Mama, I'm Alive (1977). Terekhova's subsequent work in film proved her high level of acting expertise but did not reach such great success as her earlier work.