Monitoring is a crucial process when running a project, to ensure that it contributes to a real changes for the children, their families and communities, feeds organizational learning, accountability and enhances our capacity to take action. The guide “Design and implement a monitoring system” complements Tdh’s Project Cycle Management handbook. It provides methodological markers for the teams to design and operationalize monitoring systems, which will meet strategic and operational project management requirements and ensure full participation of its stakeholders.