This document provides an introduction to a book on innovation systems in Southeast Asia. It discusses the concept of national innovation systems and how it has influenced policymakers in the region. While the concept was initially developed by European researchers, it has since caught on in Asia. The document then summarizes some of the key findings from chapters in the book that analyze innovation systems in six Southeast Asian countries. Some common themes identified are that governments continue to play a leading role in developing innovation systems, policies still focus on linear models of innovation driven by public research, and efforts are being made to strengthen linkages between actors but with limited success so far. The introduction sets the stage for comparative analyses of national innovation systems in Southeast Asia.