There is increasing momentum for the use of nature-based solutions as part of resilience-building strategies, sustainable adaptation, and disaster risk management portfolios. Awareness of nature-based solutions from communities, donors, and policy- and decision-makers is growing. This document presents five principles and implementation guidance for planning, such as evaluation, design, and implementation of nature-based solutions for flood risk management as an alternative to or complementary to conventional engineering measures. The potential users of these principles and implementation steps are professionals in risk management and climate adaptation, NGOs, donors, and international organizations. This guidance was developed in cooperation with a large and diverse group of international funding agencies, research institutes, NGOs, governmental organizations, and engineering firms. Access the Nature-Based Solutions platform run by the World Bank here.