The Sustainable Investment Institute (SII) is an outgrowth of an initiative by Portland investment professionals to explore and research the developing field of sustainable investing.  SII is a joint project of the Center for Earth Leadership and the Oregon Natural Step Network.  It is guided by a steering committee of professionals.

SII was created to advance the goal of investing in a manner that (1) promotes the goal of sustainability, (2) results in least harm to natural systems of the earth, and (3) rewards companies with sustainable business practices.  SII plans events and organizes projects to advance this goal.