在五光十色的時裝世界，新潮事物瞬息萬變，要站穩住腳必須夠台型都真材實料，而時裝界裡人人也將「RUNWAY」雜誌奉為潮流界裡的「聖經」。做得「RUNWAY」的總編輯，裴美蘭（梅麗史翠普飾）當然是時裝界裡最有權勢的大家姐，「RUNWAY」成為國際時裝界的天書，裴美蘭擁有「遇神殺神，遇佛殺佛」的狠心，任何阻頭阻勢的人將會落得淒慘下場，不合得來而被她炒魷魚的卒仔已不勝其數。裴美蘭的助手最近因為犯錯而被炒，造就了剛從大學畢業的沙安蒂(安妮夏菲維飾)一個入行良機。沙安蒂在雜誌的曼克頓總部上班，但她知道單憑著自信與鬥志打工仍未足夠。沙安蒂的最終考驗，是要得到這位全身Prada的上司的肯定。先敬羅衣後敬人，沙安蒂知道要做裴美蘭的完美助手，首先便要懂得裝備自己。變身名牌潮女的沙安蒂令男友陣腳大亂，她惡補時裝知識，起碼不會將設計大師Dolce同Gabbana調亂。與裴美蘭相處日久，沙安蒂了解到活在花花世界的惡死上司其實心靈異常空虛，她為了得到名利而付出了沉重代價，但這樣的犧牲又是否值得？

A New York writer on sex and love is finally getting married to her Mr. Big. But her three best girlfriends must console her after one of them inadvertently leads Mr. Big to jilt her.

Flighty Emily "Jacks" Jackson works for the British edition of Vogue magazine. Rather than pursue a relationship, Jacks regularly hooks up with her devoted ex-boyfriend, James Wildstone, and lives with Peter Simon, a gay screenwriter. When Jacks meets Argentinian photographer's assistant Paolo Sarmiento, she assumes he is gay and tries to bring him and Peter together, unaware that Paolo is straight and in love with her.

A playboy who refuses to give up his hedonistic lifestyle to settle down and marry his true love seeks help from a demented psychoanalyst who is having romantic problems of his own.