Comparison of stroke incidence and case fatality in different parts of the world provides information that may lead to a better understanding of the disease. In this report we have investigated these two aspects in two large populations, one in Auckland, New Zealand, and the other in Copenhagen, Denmark (the Copenhagen City Heart Study, CCHS). Incidence rates of stroke are higher for men than women in both studies. The stroke incidence rate ratios between Auckland men and CCHS men are significantly different in most age groups, whereas in women the incidence rates differ only in one age group. The age- and sex-adjusted incidence rates are higher in the CCHS for both men and women as compared to the Auckland Stroke Study. The age-adjusted incidence rate ratio is higher for men than women in both studies: 1.29 in the Auckland Stroke Study and 1.54 in the CCHS. The 28-day case fatality is also higher in the CCHS than in Auckland and is higher for women than men in both studies. The incidence rate of stroke and the 28-day case fatality is higher in the CCHS as compared to the Auckland Stroke Study in both men and women. A very high proportion of smokers in CCHS may explain some of the differences in incidence rates in the two populations.