A questionnaire study on headaches, using a door-to-door survey, was carried out in a representative sample of the general Greek population, including 1737 men and 1764 women, from 15 to 75 years of age. The parameters evaluated included age, sex, education, socioeconomic status, region of domicile, frequency of headache, use of medication, medical consultation, and family history. Latitude and climatologic factors such as humidity, temperature, and atmospheric pressure were also investigated. Headaches were not classified because the interviewers were not specialists. Nineteen percent of men and 40% of women (mean 29%) suffered from headaches in the prior year. Headaches were more frequent in lower social classes, in people with less education, and in those between 45 and 64 years of age. Nineteen percent of sufferers did not take any medication and 33% used medication every time that they had a headache, while 36% sought medical consultation. Twenty-nine percent of headache sufferers had a family history of headaches. Daily headache was present in 15% of headache sufferers. Humidity and atmospheric pressure were not correlated to headache frequency. However, in the northern areas of Greece, as well as in the regions with low mean temperature, more people suffered from daily headaches. These data may explain the lower 1-year prevalence of headaches in other Greece as compared to the prevalence of headaches in other northern European countries.