Abstract. The hypothesis that cold climate is associated with high coronary mortality in Sweden is tested. Cold exposure was calculated in each of the 284 municipalities of Sweden. There was a significant association between cold exposure and coronary mortality in both sexes in all age groups. The strongest association was found in men aged 40–64 years (coefficient of determination k = 0.39). The decile of men aged 40–64 years who lived in the coldest municipalities had a 40% excess mortality. A significant association was also found between cold exposure and mortality from cerebrovascular diseases. We conclude that there is a strong regional association between cold exposure and high coronary mortality.