The Child Cancer Foundation are celebrating their fourth Wig Wednesday on June 19.

More than 400 schools, businesses and organisations across the country are signed up for the ‘wigtastic' event, which promotes to be a fun fundraising day with a difference.

Child Cancer Foundation's Business Development Manager Claire Robb says it's simple to join in on the fun.

'All participants need to do is wear a wig on the day which can be made, bought or borrowed and make a donation to the Child Cancer Foundation. Participants can also challenge others to wear wigs as part of Wig Wednesday's ‘Big Wig Challenge' or hold their own fundraising events.

'People really got into the spirit of the event last year by wearing some incredible wigs. Importantly, over $100 000 was raised so we're hoping this year will be just as successful. After all, it's all for a good cause.”

In total, three Kiwi kids are diagnosed with cancer every week in New Zealand. The Child Cancer Foundation supports children diagnosed with cancer and their families without any government funding, so every donation really counts.

This year, some of the foundation's child ambassadors will be rocking wigs at their schools and encouraging others to get in on the fun. All Blacks legend Kieran Read and The Wiggles have also shown their support for the campaign.

To join in on the wiggy fun, simply register at www.wigwednesday.org.nz or call 0800 424 453 for more information.