Siah Chin Leong started as Manager in 1988 at the subsidiary of Tasek Maju Realty Sdn. Bhd., a Property Developer and promoted as Executive Director in 1990. He subsequently, joined Daiman Development Berhad, a Property Developer as General Manager in 2006 and resigned in 2013. Currently, he is an Advisor of S & L Vintners, a Wine Importer.