This book chapter describes key issues regarding genetic diversity of tomatoes, including taxonomy and mating system. Figures on global ex situ conservation of tomato germplasm are provided and the world’s largest collection in the public domain, held by AVRDC – The World Vegetable Center, is described in some detail. This chapter also deals with the policy framework for the conservation, access and benefit-sharing mechanisms of plant genetic resources (PGR). It describes how the policy framework and stricter phytosanitary requirements affect the exchange and use of PGR. Ways to strengthen sharing of PGR for food and nutrition security and climate change adaptation are discussed.