In this chapter we will discuss observations of climate change effects on agricultural pests in Europe, the possible mechanisms behind these observed effects and finally delve into more detail through some, relatively well studied model species (the Colorado potato beetle and the rape beetle). Direct effects of climate change on agricultural pests in Europe are difficult to dissect from all the human induced changes that have taken place in parallel with an increased mean annual temperature. During the last decade agriculture has become more professionalized in terms of land use, crop cultivation techniques and pest management strategies. We review the effect of climate change on agricultural pest by comparing the speed of range expansion of pest species to non-pest species. It seems that the poleward range shift has been faster for pest than non-pest species. We partly attribute this to the globalization of agriculture as human assisted movement has broken many natural dispersal barriers. Since the biology of many pest species is relatively poorly studied, direct conclusions on how climate change has affected biological processes of pests are challenging to make.