This publication is the proceedings of the second international conference on effective nuclear regulatory systems convened by the IAEA. The conference brought together senior nuclear safety, radiation safety and security regulators from around the world to discuss how to improve regulatory effectiveness to ensure protection of the public and the environment. The focus was on further enhancing the global nuclear safety and security regime. The conference identified several issues for consideration by governments, regulatory bodies and stakeholders, and issues for future international cooperation. These proceedings include a summary, the opening and closing speeches, the invited papers and the President’s summary. A CD-ROM which is attached to the back of this publication contains the contributed papers and presentations.