We investigated the associations between blood concentrations of lead and cadmium with stroke mortality, and potential effect modification by obesity. Our study analyzed data from 23,437 individuals aged 40 and above, using the National Health and Nutrition Examination Survey (NHANES 1999-2016) linked to the National Death Index. During a median follow-up period of 8.3 years, 336 stroke-related deaths were reported. After adjusting for potential confounders, we found that higher baseline concentrations of lead and cadmium were significantly associated with increased stroke mortality. Specifically, the hazard ratios (HRs) per doubling of metal concentrations were 1.16 (95% CI: 1.11, 1.20) for lead and 1.31 (95% CI: 1.26, 1.36) for cadmium. Stratified analysis showed that stronger associations were observed among participants who were normal weight or overweight, relative to those who were obese. In conclusion, our study demonstrates that elevated blood concentrations of lead and cadmium are significantly associated with an increased risk of stroke mortality, especially among individuals who are normal weight or overweight.