The authors probed the extent and clinical features of migraine through a community survey in the Bangkok slum. A total population of 540 individuals of both sexes were randomly selected from available subjects. They were interviewed using questionnaires. The response rate was 100%. The prevalence of migraine in the previous year in 135 men and 405 women was 10.4% and 35.3% respectively. The overall prevalence of migraine in this community was 29.1%. In both sexes, the prevalence declined with increasing age and in women, the effect of age was significant (p less than .005). The clinical features of migraine (age of onset, headache profile, neurological symptoms, severity and frequency of headache, familial history, precipitating factors and medications for headache) were analyzed. We concluded that migraine is not uncommon in a low socioeconomic group in Thailand, and that this type of headache is a burden to patients and may have some economic effect. Thus, strategy in prevention and control of migraine should be critically considered.