 She was working as the director of public relations for Dior New York in the 1960s, when she married a merchant for De Beers diamonds (Philip Harari, who she later divorced; see Personal life section below) and relocated to South Africa.From 1968 to 1970 she was an editor for South African "Vogue", a job arranged for her by Diana Vreeland.In 1976 she began the clothing company Mary McFadden Inc.

From 1982 to 1983 she was the President of the Council of Fashion Designers of America.