She co-founded Owen Healthcare, Inc. in 1969 taking the company public in 1995 before being acquired by Cardinal Health, Inc. in 1997. She served as chair of the company from 1976 until its sale. The Dian Graves Owen Foundation was formed in 1996 and still bears that name, although she now is known as Dian Graves Stai. She serves as chairwoman of the foundation, as well as chairwoman of her investment firm, Mansfeldt Investment Corp.