Climate change represents an unprecedented challenge to the world's biosphere and to the global community. It also represents a unique challenge for plant health. Human activities and increased market globalization, coupled with rising temperatures, has led to a situation that is favourable to pest movement and establishment. This scientific review assesses the potential effects of climate change on plant pests and consequently on plant health. The evidence assessed strongly indicates that climate change has already expanded some pests' host range and geographical distribution, and may further increase the risk of pest introduction to new areas. This calls for international cooperation and development of harmonized plant protection strategies to help countries successfully adapt their pest risk management measures to climate change.