We examined international variation in adult brain cancer incidence in 69 populations from a subset of cancer registries included in Cancer Incidence in Five Continents, Volume IX that met stringent quality standards. We grouped these populations into World Areas. Age-standardized incidence rates varied by World Area similarly for men and women and were highest in northern America non-Hispanic whites and Australians, followed closely behind by Europeans, then South Americans and northern America Hispanic whites. Rates among south-central Asians and northern America blacks were half to three-fifths the rates among northern America non-Hispanic whites. Rates among eastern and southeastern Asians and northern America Asians and Pacific Islanders were one-third to two-fifths the rates among northern America non-Hispanic whites. Incidence rates increased less steeply with age in the former two populations than in other populations. These results strongly suggest that populations of eastern and southeastern Asian origin, regardless of residence, have substantially lower brain cancer incidence rates than white populations, due to differences in genetic susceptibility and/or environmental/lifestyle exposures that persist in migrant populations. Male/female incidence rate ratios varied by age, but not by World Area, suggesting that this male/female difference is biologically based.