The World Health Organization (WHO) has warned of the growing threat from mosquito-borne viruses such as dengue, chikungunya and Zika. These diseases are expanding into new regions with the mosquitoes that transmit them and by 2050 the yellow fever mosquito, which is responsible for dengue transmission, could reach as far north as Chicago and Shanghai. Human behaviour has been enabling the expansion of these mosquito populations for centuries, particularly through urbanisation, travel and trade. Approaches that focus on the mosquitoes rather than the diseases themselves have the benefit of helping tackle all three of these diseases in one, and new research is focused on novel vector control methods like Wolbachia and outbreak early warning systems using climate data. Vaccines, diagnostics and antivirals will all have a role to play, but broad and adaptable responses will be crucial for the diseases that we know we need to control, as well as those that appear in the future.