Volunteers are the life and soul of Expos who give their time and energy to welcome visitors, organise events, assist with management and much more. The individuals who engage as volunteers in Expos do so for various reasons, often in reflecting a desire for personal, social or even professional development. Here, the experience of volunteering at Expo 2015 Milan is analysed based on a research study into the more than 5,000 volunteers who contributed to the success of the mega-event.1