This publication provides guidance for developing an effective lessons learned programme to enhance the strategic knowledge management initiatives of nuclear facilities and organizations. Both positive and negative experiences provide opportunities for organizations to learn and improve. These include the experience gained by individuals and teams, through business activities, and from events or incidents (both consequential and non-consequential), as well as industry experience and improvement opportunities derived from external sources. This publication includes case studies from different types of nuclear organizations and supports the development of good practices and successful approaches to lessons learned programmes.