Schools ask parents not to send any home cooking to the party over food poisoning fears.
Home-made mince pies and Christmas cake were banned from dozens of school parties in Welsh primaries this week, TES Cymru can reveal after a snapshot survey.
Instead, most parents contributed shop-bought food or were asked to bring pound;1 for teachers to buy in goodies, in a bid to stave off food poisoning.
And in one local authority - Merthyr Tydfil - even shop-bought food provided by parents is off the menu.
But while being let off the hook for baking cakes may come as a relief to busy parents, one headteacher says it has proved a real party pooper at her school. Jill Evans, head of Heolgerrig Primary School in Merthyr, said her children were disappointed.
"Years ago you would ask parents to donate food but now you can't really give the children any sort of party food other than sandwiches, sausage rolls and pizzas, and even that has to be agreed with the canteen staff."
Merthyr Tydfil borough council issued guidelines in September saying all food consumed at Christmas parties had to be prepared by local authority caterers. The move was in response to the E.Coli outbreak in autumn 2005 - an epidemic which affected 158 people within South Wales and led to the death of five-year-old Mason Jones from Deri, Bargoed.
But while the traditional Christmas party is overtaken by health and safety considerations, other festive school celebrations are still popular in Wales.
Most schools we spoke to are still celebrating Christmas with a play based on the traditional Nativity, as well as also having a cooked Christmas lunch. Most have also held a Christmas fayre and children are exchanging Christmas cards.
At St Woolos Primary School in Newport, where half of the 200 pupils are Muslim, they're having a traditional carol concert and a play called Stable Manners, a modern take on the Nativity.
Deputy head Sally Couch said: "All but two of our Muslim children are taking part, and they're children whose families withdraw them from other religious gatherings."
At Oakfield Primary School in St Mellons, Cardiff, head Dave Pedwell is putting on six different Nativity performances and a visit from Father Christmas.
He said: "We're very anxious to maintain our Christmas celebrations as well as we do with other festivals."
It was the same message at Monkton Primary School in Pembrokeshire where head William Rees said: "We will be celebrating Christian culture fully and joyfully."
However, all Christmas traditions, including homemade cakes and biscuits, are being kept for the annual Christmas dinner at Beddgelert Primary School in Gwynedd.
"I feel it's only once a year and everyone enjoys the traditions," said head Catrin Gwilym.
At Corris Primary School near Machynlleth, head Olwen Griffiths said the children would be attending a Christmas pantomime instead of having a party this year. More traditionally, it will also be holding a Christmas carol service.
"If we had a multicultural school maybe we would look at things in a different way but we don't have other religions represented here," said Ms Griffiths.
And in Colwyn Bay, deputy head Nia Jones-Artell said a traditional Nativity would be at the heart of the school Christmas play.
"It would be a great shame not to do it. Most of the pupils don't get the traditional story at home so school is only place they hear it."
Leader, page 22.