Melissa Delaware, a former foster child herself, has donated a present to the Kids in Care Christmas appeal every year. She first got the office involved four years ago, and the donations have increased every year since.

"I just asked the office staff and it went from there; if we had meetings we'd ask for donations and it's grown to where it is now," she said.

"[This year] we ended up with just over $32,000 dollars and delivered approximately 2300 presents.

"It's crazy, I didn't expect it - it's actually double what we donated last year."

As well as donations of money, which the union used to buy gifts, people donated a variety of presents including bikes, skateboards, sporting equipment, dolls and books.

Child Safety Minister Shannon Fentiman accepted the huge donation at the Brisbane region Child Safety office on Tuesday, and thanked construction industry workers for their "incredible effort".

"I know their donations will go a long way to making a brighter and happier Christmas for our children and young people who live in care," Ms Fentiman said.

"I know this generous act will be appreciated not only by our children and young people, but by their families, foster carers and loved ones."

Ms Delaware, who said Christmases as a foster child were a "bit depressing", said the Christmas presents are just a "small token" for children who find themselves in the foster care system.

"A present is only a small token; I'm not thinking we're going to change their lives, just make it a bit brighter," she said.

The donations were raised over four weeks through barbecues at building sites throughout south-east Queensland, Plumbers Union Queensland secretary Gary O'Halloran said.

"It's a great show of support and it's incredible to see how it has grown since we first started making donations to the appeal four years ago," he said.

Ms Delaware said she was not surprised by the generous response from everyone in the construction industry.

"I've worked in it for 15 years and people in the construction industry are extremely generous, extremely passionate, have a lot of empathy, and if there's someone in need you can count on people in the union movement," she said.

"It just goes to show that the industry can come together for a cause."

Ms Fentiman said there was still time to make a donation, and suggested good gift ideas to the value of $20 could include gift cards, board games, books and clothes.

For more information on the appeal, including age-appropriate gift ideas and where to drop donations, go to the GIVIT website.