A new resource that can be used with children as young as five aims to alert pupils to the way the industry uses human trafficking to produce cheap, tasty snacks.
Produced by Stop the Traffick, the pack contains lesson ideas, resources allowing pupils to mount their own anti-trafficking campaign and a story called Chaga and the Chocolate Factory, about a West African boy who is sent to work on a coastal plantation.
It also includes a handy guide to ethical chocolate.
The charity estimates that at least 284,000 children are in forced labour on the Ivory Coast after being sold to owners for as little as pound;70.
The cocoa beans produced there are bought by big conglomerates such as Nestle and provide about half the chocolate sold worldwide.
Stop the Traffick protests against human trafficking in all its forms and also produces resources focusing on the sex industry and child soldiers.
But its latest pack is more primary-friendly.
"It coincides with the bicentenary of slavery abolition, but we wanted to make a resource about children being bought and sold today," said campaigner Ruth Dearnley. "We don't want to be prohibitive and say children can't eat chocolate, but this shows them they can make a difference through what they eat. They can even press the school to change the snacks in its vending machines."