The International Masterclasses in Particles Physics (IMC) were launched by EPOG in 2005 to celebrate the International Year of Physics. Based on the idea of the Masterclasses running in the UK since 1998, in which high-school students go to a local university to interact with scientists and work with real data, EPOG added the video-conference at the end of the day to promote the scientific discussion of the achieved results between the participating institutes. In 2023 IMC reaches adulthood, in a regular activity organized every year, with increasing numbers until the start of the pandemic years. In this talk I present a brief history of IMC and of the very successful Portuguese participation, and a preliminar evaluation of its impact in the growth of the interest of portuguese students to pursue studies in Physics/Engineering Physics courses at the University. I shall present also the expected evolution of the programme, regarding topics addressed, geographical reach, target audiences and the associated website.