Susceptibility to migraine is determined by genetic factors and is therefore subject to the forces of natural selection. Migraine is a common and ancient disorder whose prevalence may be increasing, suggesting that a migraine-prone nervous system may be associated with reproductive or survival advantages. Five evolutionary explanations are reviewed that might account for the persistence of migraine: (i). migraine as a defence mechanism; (ii). migraine as a result of conflict with other organisms; (iii). migraine as result of novel environmental factors; (iv). migraine as a trade-off between genetic harms and benefits; and (v). migraine as a design constraint. An evolutionary perspective on migraine allows the generation of important hypotheses about the disorder and suggests rewarding possibilities for further research.