This publication aims to guide the assessment of water benefits resulting from interventions on natural infrastructure using hydrological models, considering the particular challenges presented in these exercises. It builds on valuable inputs, such as the Guide to Selecting Ecosystem Services Models for Decision Making, published by the World Resources Institute, and practical lessons learned from hydrological modeling exercises, mainly in the Andean region. We hope that this guide will be an accessible, useful resource for both decision makers and technical teams tasked with hydrological modeling, thus helping to bridge the science-policy gap and increasing the availability of relevant and robust information to support specific decisions.