Seven-year-old children who began school in two large Finnish cities in 1974 were investigated for the occurrence of migraine and other headache; the pupils were again surveyed at the age of fourteen. A total of 2921 pupils participated in both studies. By the age of seven, headache had occurred in 37% and migraine in 2.7%; at the age of fourteen the figures were 69% and 10.6% respectively. In the group under eight years migraine was more common in boys than in girls, but in groups older than that girls were in the majority. The prognosis for migraine which had begun before or at the age of seven was better for boys than for girls, while in girls more often than in boys migraine which began in the early school years disappeared by the age of fourteen years.