This operational guidebook demonstrates the importance of both supplementing nutrition programmes with WASH activities and adapting WASH interventions to include nutritional considerations i.e. making them more nutrition-sensitive and impactful on nutrition. It has been developed to provide practitioners with usable information and tools so that they can design and implement effective WASH and nutrition programmes. Apart from encouraging the design of new integrated projects, the guidebook provides support for reinforcing existing integrated interventions. It does not provide a standard approach or strict recommendations, but rather ideas, examples and practical tools on how to achieve nutrition and health gains with improved WASH. Integrating WASH and nutrition interventions will always have to be adapted to specific conditions, opportunities and constrains in each context.