These International Association for Impact Assessment (IAIA) Indigenous Peoples and Traditional Knowledge Best Practices Principles aim to promote a meaningful integration of traditional knowledge as well as the respectful incorporation of Indigenous Peoples in impact assessment. This document: • Describes ways to successfully incorporate Indigenous Peoples positions throughout the impact assessment process. • Highlights ways to use traditional knowledge along with `western knowledge` to complete a more comprehensive assessment. The first half of this document provides the background, definitions and objectives of best practices principles. The second half presents the best practice principles, organized into general “basic principles” and specific “operating principles.”