In the last few years the collection has expanded considerably; it is now considered to be one of the most important private collections related to fashion in the world (as ranked by Elle USA in November 2010). The Alexandre Vassiliev Foundation has amassed over 50,000 items and includes vintage clothing, predominantly European, from the early eighteenth century until the present day, and various fashion accessories. The Alexandre Vassiliev Foundation also holds a large collection of photographs and a library related to fashion.

From the eras of Louis XV and Louis XVI, the Foundation is preserving a large collection of aristocratic clothing, originating from the collections of the Brooklyn Museum and the Metropolitan Museum in New York. The eighteenth section also holds a rich collection of French, English and Italian fans, as well as purses, wallets and corsets from the gallant century. Inevitably, the biggest names in French Haute Couture and European fashion are included in this section. The collection retains a rare dress created by the first fashion house branded “Worth & Boberg”. The nineteenth century is well represented in the collection of the Foundation, Alexandre Vassiliev having a particular liking for that time period. It contains a large quantity of beaded items (purses, mittens), nosegay, dance cards, lorgnettes, wallets and purses, parasols, firebreaks, bracelets, perfume bottles, mosaic (pins, bracelets and romantic objects), and stockings, suspenders and shoes.

This rich collection has been the subject of specialized studies which have been published in various books and catalogues and public exhibitions of the collection are regularly held.

The Alexandre Vassiliev Collection has a particular focus on objects of fashion that are linked to major political upheavals, revolutions and war. The Foundation holds a large collection of clothing associated with the First World War, the entire wardrobe of the Russian millionairess Tatiana Samsonov, clothing associated with the Russian Revolution and Soviet fashion behind the Iron Curtain. There is a large collection of French and German clothing from the Second World War which includes dresses, hats, shoes, jewellery and cosmetics (powder, blush, cream, lipstick, perfume).

The Foundation is proud to preserve some artworks from the greatest French houses such as Doucet, Paquin, Poiret, Chanel, Schiaparelli, Dior, Courreges and others. Artworks of international houses such as Redfern, Fortuny and Babani are also preserved.

The twentieth century contributes the richest part of the collection and consists of thousands of dresses made between 1900 and 2000 by major fashion couture houses as well as ready-to-wear, sometimes having belonged to great personalities such as the Duchess of Windsor, Lauren Bacall, Leslie Caron, Romola Nijinski, Fafzia Princess of Egypt, Eleonora Duse and others.

The Alexandre Vassiliev Foundation reflects a great interest in the cultural phenomenon of the Ballets Russe. The collection includes costumes designed by Leon Bakst for Diaghilev, by Natalia Goncharova, Michel Larionov, Pablo Picasso, Raoul Duffy, Erte, and Waquewitch. There are also souvenirs of Russian Ballet that belonged to Tamara Toumanova, Irina Baronova, Alexandra Danilova, Maya Plisetskaya, Galina Panova, and many others.