Pooled analysis of major placebo-controlled trials suggests that the earlier thrombolysis is given after ischemic stroke, the better the outcome. We report a single-center assessment of the effect of ultraearly thrombolysis on the outcome of our patients. Between January 2003, and December 2008, a total of 878 patients with ischemic stroke received thrombolysis within 4.5 hours from the symptom onset at the Helsinki University Central Hospital. Using univariate methods and multivariable logistic regression, we assessed the association between onset-to-treatment time (OTT) and favorable 3-month outcome (modified Rankin Scale 0 to 2). Median age was 70.5 years, median OTT 115 minutes, and median National Institutes of Health Stroke Scale (NIHSS) on admission 9. After adjustment for baseline stroke severity, more patients with OTT <70 minutes had a favorable outcome than those with OTT > or = 70 minutes. Specifically, OR of 5.15 (1.50 to 27.5) was for the patients with NIHSS 7 to 12, and 2.74 (1.26 to 5.90) for those with NIHSS > or = 13. Of the patients with OTT < or = 90 minutes, those with NIHSS 7 to 12 had an OR of 1.72 (1.00 to 2.96) for a favorable outcome, and those with NIHSS > or = 13 had lower mortality than the ones with OTT >90 minutes (16.4% versus 29.5%; P=0.01). Multivariable model showed an association of better outcome with lower baseline glucose level, younger age, lower baseline NIHSS, and OTT <70 minutes. Ultraearly thrombolysis was associated with better outcome of our patients with stroke with moderate or severe symptoms. The earlier the treatment was given, the higher the likelihood of favorable outcome.