Background and Purpose—Coronary heart disease (CHD) and stroke are leading causes of death and disability. Because they share major common risk factors, it would be expected that trends in mortality and incidence of these 2 major cardiovascular diseases would be similar.Methods—Data from the World Health Organization (WHO) Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) Project were used to compare 10-year trends in mortality, event rates, and case fatality from both CHD and stroke. Fifteen populations in the WHO MONICA Project provided data on both CHD (60 763 events) and stroke (10 442 events) in men and women aged 35 to 64 years (23.4 million person-years of observation in total).Results—Trends for the 2 cardiovascular diseases varied within and between populations, and when data from all populations were combined, trends in CHD and stroke mortality differed in men (P=0.001) but not in women, whereas trends in event rates differed significantly in both men and women (P<0.001 andP=0.011, respectively). The differences in trends for CHD and stroke case fatality were not statistically significant in either men or women. In sensitivity analyses, differences in trends in event rates remained statistically significant in men (P<0.001) but not in women.Conclusions—Trends for CHD and stroke mortality rates, event rates, and case fatality differ substantially between and within the study populations.