Over three decades, a number of international and national organizations have provided technical and financial support to community seed banks around the world. Only a few of these organizations have developed and published a practical guide about how they have offered this support. This handbook fills the gap and advances research and capacity development regarding community seed banks. The publication Community seed banks: origins, evolution, and prospects edited by Ronnie Vernooy, Pitambar Shrestha, and Bhuwon Sthapit (Vernooy et al. 2015), which offers a global overview of diverse community seed banks around the world, provided the foundation for the content of this handbook. Parts of that publication have been updated and integrated into the handbook.