The BT Young Scientist and Technology Exhibition gets underway today.
The event is now in its 50th year and will see around 550 student projects on display at the RDS in Dublin.
Official judging commences today with the exhibition opening to the public from tomorrow.
The annual competition is expected to attract over 40,000 people, making it one of the largest events of its kind in Europe.
Organisers says it is set to be the biggest ever this year, with 2,000 ideas submitted by 4,418 students from across 32 counties.
Some 50% of secondary schools in the Republic of Ireland have entered a project for the event.
The CEO of BT Ireland Colm O'Neill says the event will be open to the public from tomorrow.
"From this morning people will be in setting up their stands, we'll then have the opening ceremony in the early afternoon and the first round of judging commences this afternoon," he said.
"Then we open the exhibition to the public on Thursday morning, and then judging will continue through Thursday, Friday until Friday evening - we will announce who the winner of the BT Young Scientist 2014 is."