Emulating Renato Castellani, who had previously in 1960 filmed Romeo and Juliet on location in an Italian hill city, Franco Zeffirelli, veteran stage and opera director, combined the neo-realism of Italian cinema with the unabashed sentimentality of a Puccini opera in making this enormously popular adaptation of Shakespeare’s tragedies of young lovers. Moreover he filtered the action through the lens of Leonard Bernstein’s West Side Story to make the experience totally palatable to the rebellious youth of the late Sixties. What he sacrificed in Shakespeare’s language (and perhaps half or more of the text disappeared), he attempted to compensate for with a colorful and visually appealing panorama of life in a northern Italian city. Zeffirelli had previously accomplished much the same results with his filmed 1966 Taming of the Shrew (598) starring Richard Burton and Elizabeth Taylor. Moreover he also brought to the venture considerable experience as a director of staged Shakespeare for the RSC and other companies. Hundreds of aspirants were auditioned before lucky, then 14-year-old, Olivia Hussey snapped up the prized role as Juliet
Description from Shakespeare on Screen : an International Filmography and Videography by Kenneth S. Rothwell and Annabelle Henkin Melzer.