Fifty migraineurs were asked if insufficient fluid intake could provoke their migraine attacks. Twenty replied "yes," 7 were doubtfully positive, and 23 said "no." In addition 14 of 45 migraineurs at a meeting of the British Migraine association (UK) also recognized fluid deprivation as one of their migraine triggers. Thus a total of 34 of 95 migraineurs knew that dehydration could provoke their attacks, a precipitant not recognized by the medical profession. This indicates that we can add fluid deprivation to our list of migraine precipitants. It would be interesting to know the extent to which it applies in other climates. Further research is needed into the mechanism of this precipitant.