BackgroundThe prevalence of stroke disability associated with high BMI has significantly increased over the past three decades. However, it remains uncertain whether high body-mass index (BMI) exerts a similar impact on the disease burden of different stroke subtypes. The aim of this study is to assess the long-term trends of stroke and subtypes mortality attributable to high BMI in China between 1990 and 2019.MethodsData on stroke and subtypes mortality attributable to high BMI in China was extracted in the Global Burden of Disease (GBD) 2019. The trends of age-standardized mortality rate (ASMR) were calculated using the linear regression and age-period-cohort framework.ResultsThe changing trend of ASMR on stroke attributable to high BMI in China differed among subtypes, with an estimated annual percentage change (EAPC) and 95%CI of 2.04 (1.86 to 2.21) for ischemic stroke (IS), 0.36 (-0.03 to 0.75) for intracerebral hemorrhage (ICH), and − 4.62 (-5.44 to -3.78) for subarachnoid hemorrhage (SAH). Net and local drift analyses revealed a gradual increase in the proportion of older people with IS and a gradual increase in the proportion of younger people with hemorrhagic strokes. The cohort and period rate ratios varied by subtype, showing an increasing trend for IS and ICH but a decreasing trend for SAH. The stroke mortality attributable to high BMI increased significantly with age for IS and ICH, peaking between ages 50–70 for SAH. Notably, males had higher ASMR related to stroke but exhibited slighter declines or higher growth compared to females in China. Moreover, the population affected by fatal strokes tended to be older among females but more evenly distributed across a wider age range encompassing both younger and older individuals.ConclusionThe research findings indicate a rising trend in the ASMR of stroke and subtypes attributable to high BMI in China from 1990 to 2019, with different patterns of change for different subtypes, genders and ages. Consequently, it is imperative for public health authorities in China to formulate guidelines for specific stroke subtypes, genders and ages to prevent the burden of stroke attributable to high BMI.