Comedian Urzila Carlson, Breast Cancer Foundation ambassador, said: "Eight Kiwi women are diagnosed with breast cancer, on average, every day.
"And every dollar raised through this initiative will go a towards supporting women battling the disease, and to the continued research that's necessary to combat it."
Breast cancer is the most common cancer for women, affecting one in nine New Zealand women over their lifetime. Although uncommon, men can get breast cancer too.
Tragically, around 650 women die of the disease every year.
Carlson issued a challenge to customers of the national supermarket chain. "Let's face it, the more people who get behind this, the more Pak'nSave will have to donate," she said. "So have a poke around your dress-up box, get down to your local store, upload a selfie, and get Pak'nSave to dig deep and donate to a great cause."
Customers shouldn't be worried if their costumes aren't too flash.
"You can make a suit out of cardboard boxes, or just wrap yourself in tin foil," Steve Bayliss, Foodstuff NZ's general manager of marketing, added.