Laurence Harvey, as Romeo, was already an experienced screen actor, who would shortly take over roles intended for the late James Dean in Walk on the Wild Side and Summer and Smoke.

[4] By contrast, Susan Shentall, as Juliet, was a secretarial student who was discovered by the director in a London pub, and was cast for her "pale sweet skin and honey-blonde hair.

[6] The film was shot at Pinewood Studios near London and on location in Italy, utilizing Renaissance-era architecture in Verona, Venice, Siena, and other cities.

Some of Castellani's changes have been criticised as ineffective: interpolated dialogue is often banal, and the Prince's appearances are reimagined as formal hearings, undermining the spontaneity of Benvolio's defence of Romeo's behaviour in the duel scene.

[1] The major supporting roles are vastly reduced, including that of the nurse; Mercutio becomes (in the words of Daniel Rosenthal) "the tiniest of cameos", as does Tybalt, and Friar Laurence "an irritating ditherer",[6] although Pauline Kael, who admired the film, praised Mervyn Johns's performance, claiming that he transformed the Friar from a tiresome presence to "a radiantly silly little man".

[9] Castellani uses competing visual images in relation to the central characters: ominous grilles (and their shadows) contrasted with frequent optimistic shots of blue sky.