[3] During World War II, in her preadolescence, Košćina was brought to Italy to live with her older sister, who had married an Italian citizen.

(1955) by Camillo Mastrocinque, leading to her breakout role, portraying Giulia, daughter of the train engineer Andrea, in Pietro Germi's The Railroad Man (1956).

Koscina was suited to sophisticated comedies like Mogli pericolose (Dangerous wives, 1958), where she made a direct sentimental challenge to poor Giorgia Moll.

From the early 1960s, she invested most of her considerable earnings in a luxurious villa, in the well-to-do district of Marino, Rome, complete with 16th-century furniture and artistic paintings.

Living with Raimondo Castelli since 1960, they did not marry due to then Italian law and because his wife Marinella refused to give him an annulment.

[7] After turning 30, she partnered with actors such as Kirk Douglas in A Lovely Way to Die (1968) and Paul Newman in The Secret War of Harry Frigg (1967), but without any luck.

[citation needed] She also starred in the 1967 comedy caper Three Bites of the Apple with David McCallum, and Deadlier Than the Male (1967), in which Elke Sommer and she portrayed sophisticated professional killers dueling with Bulldog Drummond.

The Piper Club [it] opened in 1965 during the "dolce vita" era and was a destination of choice for the international jet set interested in what was new in art, culture and music.