Hélène Ostrowska was born in Monte Carlo, Monaco, in 1907, the daughter of Ukrainian-Polish parents, Michel Ostrowsky and Cécile Werblovska.

[1] Shortly after the Second World War,[4] Arpels opened a small boutique in midtown Manhattan, selling contemporary versions of embroidered Arabian kaftans, intended to be worn as "bohemian eveningwear".

[1][5] Regular customers included Jacqueline Kennedy Onassis, and Arpels became her friend and fashion advisor for over 20 years.

[1] Her business partner in these ventures was Andre Azria, a Tunisian émigré living in New York, who in the 1950s had moved to the US, and managed the retail side.

[5] Other customers included Betsy Bloomingdale, Leonore Annenberg, Nancy Reagan, Lily Auchincloss, and Bette Midler.