It is well recognized that headache, and especially migraine, runs in families. Recent studies into the heritability of primary headache subtypes, migraine, cluster and tension headache, and conditions in which headache is a prominent feature, such as the mitochondrial disease, mitochondrial encephalopathy, lactic acidosis, and strokelike episodes, and the arteriopathy, cerebral autosomal-dominant arteriopathy with subcortical infarctions and leukoencephalopathy, are improving our understanding of the genetic contribution to headache. Studies of the rare familial hemiplegic migraine are leading to advances in understanding the pathophysiological mechanisms of the more common migraine types. Current knowledge of hereditary and genetic features of headache subtypes is reviewed and the implications for understanding the pathophysiology of migraine are discussed.