Increased blood pressure (BP) variability predicts cardiovascular disease, but lack of operational thresholds limits its use in clinical practice. Our aim was to define outcome-driven thresholds for increased day-to-day home BP variability. We studied a population-based sample of 6238 individuals (mean age 60.0±12.9, 56.4% women) from Japan, Greece, and Finland. All participants self-measured their home BP on ≥3 days. We defined home BP variability as the coefficient of variation of the first morning BPs on 3 to 7 days. We assessed the association between systolic/diastolic BP variability (as a continuous variable and in deciles of coefficient of variation) and cardiovascular outcomes using Cox regression models adjusted for cohort and classical cardiovascular risk factors, including BP. During a follow-up of 9.3±3.6 years, 304 cardiovascular deaths and 715 cardiovascular events occurred. A 1 SD increase in systolic/diastolic home BP variability was associated with increased risk of cardiovascular mortality (hazard ratio, 1.17/1.22; 95% confidence interval, 1.06-1.30/1.11-1.34; P=0.003/textless0.0001) and cardiovascular events (hazard ratio, 1.13/1.14; 95% confidence interval, 1.05-1.21/1.07-1.23; P=0.0007/0.0002). Compared with the average risk in the whole population, risk of cardiovascular deaths (hazard ratio, 1.66/1.84; 95% confidence interval, 1.27-2.17/1.42-2.37; P=0.0002/textless0.0001) and events (hazard ratio, 1.46/1.42; 95% confidence interval, 1.21-1.76/1.17-1.71; Ptextless0.0001/0.0004) was increased in the highest decile of systolic/diastolic BP variability (coefficient of variationtextgreater11.0/12.8). Increased home BP variability predicts cardiovascular outcomes in the general population. Individuals with a systolic/diastolic coefficient of variation of day-to-day home BP textgreater11.0/12.8 may have an increased risk of cardiovascular disease. These findings could help physicians identify individuals who are at an increased cardiovascular disease risk.