This paper is the fourth in a series published by the International Labour Organization (ILO) that synthesizes the knowledge and experience acquired from implementation of the West African Cocoa and Commercial Agriculture Project to Combat Hazardous and Exploitive Child Labour (WACAP). It reviews the WACAP experience of child labour monitoring and highlights the elements and issues that were critical to the lead-up, design, start-up and success of the community-based monitoring systems in Ghana and Cote d'Ivoire.