Some clubs had a very early start with people travelling from as far afield as Letterkenny, Klifeacle and Ballina and from as close as Ratoath and Boyne.
Stephen Gregory, Creggs RFC minis coach, said: "This is a great day for mini rugby, the organisation and work the IRFU and Aviva have put into this has been first class.
"This is my fourth year with the mini rugby and it's great to see the youngsters growing, getting stronger and to see their rugby skills improve."
The kids involved were as keen to talk about Ireland's chances in New Zealand as they were to tell us how they were enjoying the day.
Tom Martin from Cill Dara said: "We are having great fun, I've scored a few tries. I've been watching the World Cup and I think we're going to make it to the final!"
Joey Keane from Ennis was enjoying the day despite the weather. "We are wet but having great fun," he said.
Donal Roche, minis coach at host club Ashbourne RFC, was delighted with the day. "I've been involved for about four years - even with the weather today everyone has a smile on their face, we're just delighted to be here - we just wish it could last longer!"