Ho joined Temasek Holdings as a Director in January 2002 and became its Executive Director in May 2002. The then-chairman of Temasek Holdings, former Cabinet minister S. Dhanabalan, said Ho was the best person for the job because of "a willingness on her part to take calculated risks". She assumed the role of Chief Executive Officer of Temasek on 1 January 2004. She is widely credited with transforming Temasek, an investment company owned by the Government of Singapore, from a Singapore-focused firm into an active investor in Asia and the world.