Objective:To compare access to intravenous thrombolysis (IVT) for acute ischemic stroke (AIS) and its outcomes in patients with and without dementia.Methods:This was a longitudinal cohort study of the Swedish dementia and stroke registries. Patients with preexisting dementia who had AIS from 2010 to 2014 (n = 1,356) were compared with matched patients without dementia (n = 6,755). We examined access to thrombolysis and its outcomes at 3 months (death, residency, and modified Rankin Scale [mRS] score). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with logistic and ordinal logistic regression.Results:The median age at stroke onset was 83 years in both groups. IVT was administered to 94 (7.0%) patients with dementia and 639 (9.5%) patients without dementia. The OR of receiving IVT was 0.68 (95% CI 0.54–0.86) for patients with dementia. When the analysis was repeated exclusively among patients independent in everyday activities, dementia status was no longer significant (OR 0.79, 95% CI 0.60–1.06). However, differences persisted in patients ≤80 years of age (OR 0.58, 95% CI 0.36–0.94). In patients who received thrombolysis, the incidence of symptomatic intracerebral hemorrhage (sICH; 7.4% vs 7.3%) and death at 3 months (22.0% vs 18.8%) did not differ significantly between the 2 groups. However, mRS score and accommodation status were worse among patients with dementia after 3 months in adjusted analyses (both p < 0.001). Unfavorable outcomes with an mRS score of 5 to 6 were doubled in patients with dementia (56.1% vs 28.1%).Conclusions:Younger patients with dementia and AIS are less likely to receive IVT. Among patients receiving thrombolysis, there are no differences in sICH or death, although patients with dementia have worse accommodation and functional outcomes at 3 months.