Age-adjusted mortality rates from coronary heart disease (CHD) and other causes were examined in Minnesota for the years 1960-1978. Regions differed in CHD mortality levels and time trends. The greatest decline in CHD mortality occurred in the Twin Cities. The Northeast region had the highest CHD mortality. Influenza and pneumonia death rates were unrelated to CHD trends. Stroke mortality, which also declined sharply, showed no regional differences. Cancer mortality was highest in the Twin Cities and Northeast regions and increased significantly over the period; most of this increase was due to a striking increase in lung cancer mortality. The authors conclude that: (1) the CHD mortality decline in Minnesota was similar to that in the United States; (2) regional differences within the state in CHD mortality levels and trends were statistically significant; (3) CHD trends were not explained by influenza epidemics; (4) regions differed in mortality rates for hypertension in the same way as they did in CHD mortality, but differed little in stroke mortality. This leaves unclear the role of hypertension in regional CHD differences. (5) Trends in cancer mortality indicate that a general decline in mortality, due to factors affecting a wide variety of diseases, does not explain the downward trends in CHD mortality.