The Eighth International Workshop on Volcanic Ash (IWVA-8) was held in Rotorua, New Zealand on 4 and 5 February 2023. Its purpose was to demonstrate the worldwide progress made in supporting the scientific and technological advancement within the international airways volcano watch (IAVW) over the past 10 years or more and to highlight where gaps and other limitations in capacity and capability still prevail. The IAVW is a worldwide system comprising meteorological, volcanological, geological and other facilities and services supporting continued safe and efficient aviation operations whenever and wherever volcanic eruptions are occurring and/or whenever and wherever volcanic ash clouds and gases are present in the atmosphere. Responding to the evolving needs of the aviation industry, the workshop sought to chart a path for scientific and technological advancement through the 2020s and beyond, thereby helping to inform the further development of the work plans of WMO and partner agencies. Suggested citation: World Meteorological Organization, 2023: Proceedings of the Eighth International Workshop on Volcanic Ash (AeM SERIES No. 8). Geneva.