Retailers are said to be stocking their shelves with slim suits, skinny ties, sheath dresses and pearls in readiness for the autumn.
Kevin Harter, the vice-president of fashion direction at Bloomingdale's, said: "As far as TV shows go, Mad Men probably has the most influence on fashion. And we're going to see this influence continue."
The store has featured Mad Men window displays and is staging an event with cast members at the end of September.
John Slattery, one of the stars of the series, features in a six-page fashion spread in GQ's August issue.