Visitors flocked to the Whanganui War Memorial Centre to view hundreds of miniature worlds made from Lego bricks and accessories.
As well as farms, fire stations and castles, there were displays of Star Wars, Harry Potter and other Lego series creations.
Organiser Erina Cresswell said there were 2000 visitors on Saturday and they were expecting similar numbers on Sunday.
There were hundreds of displays and Lego pits for children to create their own displays as well as kits and accessories for sale.
"It's been a fantastic response and thanks to great sponsorship we've been able to offer a lot of great raffles and prizes."