Christmas wrapping paper, Christmas trees and soccer all contributed to Christmas Day injuries last year, ACC says.
Every year people enjoying Christmas Day came a cropper and injured themselves, ACC said.
Last year almost 4000 people injured themselves on 25 December, costing the country about $4 million.
Among Christmas Day injuries reported last year, about 20 involved giftwrap, and 113 people reported injuries connected to Christmas trees and decorations.
ACC injuries prevention leader Kirsten Malpas said: "That could be anything from the tree falling on them, to using something that's not the best device to get up and put the lights up the tree, so not a ladder or anything like that, but maybe a wobbly stool".
"The mind boggles," Malpas said, when discussing how people were able to injure themselves with giftwrap.
By far the most common injury on Christmas Day was traditionally falls; last year almost 60,000 people reported injuries from falls, and 24,400 of those were in the home.
Malpas said that with relatives crowded into houses together, many people enjoying a few drinks, and new presents being tested, houses were rife with trip hazards.
Extension cords were a particular risk because they were often set up across walkways temporarily to power appliances being used while guests were visiting.
Another big injury risk factor for Christmas Day and the holiday season was people suddenly escalating their activity level and injuring themselves.
Time off from work and friends and family getting together meant dusty sports equipment was brought out of the shed, and people roared back into activities they hadn't done all year.
Watersports, soccer and cycling accounted for many of the recreation and sport injuries at this time, Malpas said.
"People get their shiny new Christmas present, which might be a bike or a kayak or something like that, and there are people that come unstuck.
"I think football's [a common injury factor as it's] one of those sports where people will just have the ball in the backyard or at the beach, so it's a bit more casual, with a bunch of people - you don't need a team to have a bit of a kick around.
"And there are an awful lot of people across the country that have bikes, and they say 'this is the year I'm going to use my bike, and get out there', and quite a few people get bikes for Christmas, so you get kids learning to ride."
In general, Malpas said there'd been a notable rise in the number of electric-bike injuries, as the powered bikes have become more common.
"With ... e-bikes you potentially had someone that learned to bike as a kid, and then in their 50s they go 'I'm going to get an e-bike', which is great, but there's quite a bit of time between them learning the basics, and the road environment has changed."
A bicycle helmet was an important must for all bike riders, not an optional extra, and a dose of caution with new toys and summer activities was the best way to make the most of the season, Malpas said.
"Have a bit of an assessment of what your ability is, so you don't overextend yourself.
"Particularly at this time of year, and more so with Covid, I think people are a lot more tired going into this Christmas than perhaps in the past - and fatigue we know is a factor in quite a bit of injury."
Malpas said summer was a great time to ramp up activity levels again, but slowly, with pacing and plenty of stretches.