Some 550 projects have made it through to 51st BT Young Scientist and Technology Exhibition.
Some of the 1,200 students involved are setting up their stands this morning and the official opening takes place.
The event at the RDS is open to the public from Thursday to Saturday.
Tickets are available at the door costing €6 for students, €12 for adults and €25 for a family pass.
As well as the student projects on display, the venue will be packed with science and technology exhibits and shows.
In addition TITAN - the 7ft android robot - makes a much anticipated return to the exhibition, Dr Who's Daleks and Star Wars R2D2 go head-to-head in The World of Robots and visitors can also enjoy a trip aboard the International Space Station through a 3D simulation.
People can plan their visit to the RDS in advance by downloading the new BT Young Scientist and Technology Exhibition app.
Dr Peter Taylor is a former winner and now a judge in the competition. And he also comes from one of the most famous households in Ireland.
Mari Cahalane from the exhibition says the standard of projects this year is very high.
