This Toolkit offers guidance to achieve, through Nature-based Solutions (NbS), a 'triple win' to enhance biodiversity, address climate change, and reduce poverty in the context of Official Development Assistance (ODA) spend, especially for the International Climate Finance (ICF) programme. The toolkit is a summary of the current state of knowledge and core Principles for effective and efficient delivery of NbS. Implementation Guidance builds on these Principles to present key considerations and possible tools to achieve the triple win. The Toolkit highlights the need to treat the conservation or enhancement of biodiversity as an explicit objective on par with addressing the impacts of climate change and reducing poverty. Biodiversity Indicators in Context also provides recommendations to measure the impact of Nbs interventions on biodiversity from the project to portfolio scale. Finally, a review of the Economics and Financial Assessment presents a brief discussion of how benefit-cost ratios and value for money assessments vary for selected interventions. It also outlines barriers to private investment in Nbs with possible models for leveraging private finance.