This report contains lessons to improve the ongoing response, many of which have already been acted upon. It also contains lessons for the organization, as well as the wider humanitarian community, about responding to situations of rapid mass displacement and settlement. The evaluation contributes to improving UNICEF’s work to serve children in Cox’s Bazar and around the world. This evaluation piloted ‘Real-Time Evaluations Plus’, an innovative approach in which the standard evaluation stages are compressed; an Evaluation Office staff member is embedded in the team and a more participatory approach is taken. This approach aims to produce evidence quickly enough to enable timely decision-making and to enhance the utility of the evaluation.