Background: Tenecteplase is increasingly used off-label as an alternative to alteplase for ischemic stroke thrombolysis. Our aim was to evaluate the safety of tenecteplase versus alteplase in comprehensive real-world data. Methods: We compared the outcomes for adult patients with acute ischemic stroke treated with alteplase or tenecteplase, registered in the Swedish Stroke Register between January 1, 2018 and December 31, 2020. The primary outcome was symptomatic intracerebral hemorrhage or death during hospital stay. Secondary outcomes were death within 90 days, modified Rankin Scale at 90 days, and mean door-to-needle time (DNT). Results: There were no significant differences in age or risk factors between 6,560 patients (45% women, mean age 74) treated with alteplase and 888 patients (43% women, mean age 74) treated with tenecteplase, although tenecteplase was more commonly used in non-university hospitals, hospitals with high use of thrombolysis, and in wake-up strokes. Tenecteplase was not non-inferior compared to alteplase in terms of symptomatic intracerebral hemorrhage or death during hospital stay (13.2% vs. 10.7%, absolute risk difference [95% confidence interval, CI] 2.5% [0.1 to 4.9%], adjusted odds ratio 1.44 [1.07–1.94]). There were no significant differences in functional outcome or death at 90 days, but tenecteplase was associated with decreased DNT (mean difference 9 min). Conclusion: Tenecteplase was not non-inferior in safety outcome, although associated with decreased DNT. As accumulating randomized controlled studies support the non-inferiority of tenecteplase regarding functional outcome, it is important to keep scrutinizing the safety outcomes.