Rapid climate change is widely acknowledged as the greatest challenge facing life on earth. The potential impact of climate change on the broad portfolio of underutilized plant species has not been assessed. The impacts of climate change on wild underutilized species, will vary, depending on their natural distribution, nature of predicted changes, adaptive and resilience capacities, ability to migrate, dispersal capacity, nature and ecology of their new bioclimatic envelopes and their ability to survive in them and colonize new areas. The availability of pollinators and dispersal agents, the environment and the management practices that might be associated with the species will also be important. Less clear is the scenario regarding underutilized cultivated species, whose survival is dependent not only upon their resilience and adaptation but also on our own ability to recognize and promote sustainably their use in a context of changing markets, food trends and life styles (aspects whose coverage goes beyond the scope of this book). Out of an estimated portfolio of 30,000 edible plant species recorded worldwide, humankind depends upon just 12 crops for the bulk of its nutritional requirements. This situation has major implications for the future of food security and wellbeing and its gravity can be perhaps better appreciated today in the context of current debates over the future of the planet in climate changing scenarios. While many underutilized species may be at risk like other major crops due to climate change, the global community needs to recognize and appreciate that these very same species may hold the key to a food-secure future as this chapter highlights. On the other hand, underutilized species (wild or cultivated), may hold as well the key to future agro-ecosystem diversification and adaptation. Minimizing the threats and ensuring the conservation and sustainable utilization of these species is one of the greatest challenges we must address in the decades to come.