Long-term trends in PM_2.5-attributable cardiovascular diseases (CVDs) and subtypes mortality remain unclear between China and India, facing dual challenges of aging and severe air pollution. We aim to compare long-term trends and age-, period-, and cohort-effects changes in PM_2.5-attributable CVD and subtypes mortality in China and India from 1990 to 2019. Data are derived from Global burden of disease 2019. Long-term trends and age-, period-, and cohort-effects changes were evaluated by join-point regression and age-period-cohort models. We found that in China, the age-standardized mortality rate in CVD potentially increased in 1990–2012, followed by a significant downwards trend in 2013–2019, while the rate was obviously upward in India from 1990 to 2019. The impact of PM_2.5 on CVD and subtypes mortality increased sharply with age in both countries. The period risk ratios (RRs) began to significantly decline in 2010–2014 in China, while India revealed a noticeable increase during the 30 years. The cohort RRs are still increasing among the younger generation in China, while the impact in India is not as pronounced. These findings suggest that the older adults are more susceptible to the effects of PM_2.5. And compared with India, the PM_2.5 hazards in China have begun to reduce because of the early implementation of strict air pollution control policies, suggesting that it is more necessary for India to conduct strict and efficient air pollution control policies to increase the health benefits.