It's made up of almost half a million pieces, weighing 3.5 tonnes in total.
The 10m tall Lego Christmas tree in Auckland's Aotea square is New Zealand's biggest ever Lego build.
Ryan 'The Brick Man' McNaught worked with six other people constructing it in a studio over six weeks.
"It's the largest Christmas tree made out of Lego in the southern hemisphere," he said.
The bricks would fill "two shipping containers" and the tree display took 1,200 hours to complete.
"Because it's so big we actually have to get real engineers to sign it off, not us Lego engineers. It has to be wind-rated, safe."
Children and parents alike were admiring the construction this morning.
"We've all had a [Lego] experience. Even as parents and adults, we played with it as a kid. Now that our kids are playing with it there's a generational thing happening.
"The kids get freaked out by it because it's so big and awesome. Then dad's sitting there thinking 'how on earth did they do that?' Mum's going 'that would cost so much!'"
LED lights on the tree will be switched on at 8pm by Auckland Mayor Phil Goff.