Celebrated but impetuous film director Guido Contini, succumbing to the pressures of filming his latest film epic (a musical version of the Casanova story), suffers a midlife crisis. One by one, women from his past and present – including his mother, his wife, his mistress, and his leading lady – haunt, instruct, scold, seduce and encourage him until he finally learns to grow up.

Nine was also adapted into a major motion picture from Rob Marshall, the acclaimed director of the 2002 film version of Chicago. Of the Broadway musical, Marshall said it is "a sumptuous and emotional work that translates naturally to the film musical genre because of its seamless relationship between fantasy and reality." Composer and lyricist Maury Yeston worked on the film adaptation and created three new songs for the movie musical, which was released in December, 2009.