BACKGROUND: Acute stroke is a time-critical emergency where diagnosis and acute management are highly dependent upon accuracy of patient’s history. We hypothesised that language barrier is associated with delayed onset time to thrombolysis and poor clinical outcomes. AIM: To evaluate the effect of language barriers on time to thrombolysis and clinical outcomes in acute ischemic stroke. METHODS: This is a retrospective study of all patients admitted to a metropolitan stroke unit (Melbourne, Victoria, Australia) with an acute ischemic stroke treated with tissue plasminogen activator between 1/2013 and 9/2017. Baseline characteristics, thrombolysis time intervals, length of stay, discharge destination, and in-hospital mortality were compared between patients with and without a language barrier using multivariate analysis after adjustment for age, sex, stroke severity, premorbid modified Rankin Scale (mRS) and Charlson Comorbidity Index (CCI). Language barriers were defined as a primary language other than English. RESULTS: A total of 374 patients were included. Of this, 76 patients (20.3%) had a language barrier. Mean age was 5 years older for patients with language barriers (76.7 vs 71.8 years, P=0.004). Less non-English speaking patients had pre-morbid mRS score of zero (P=0.002) and more had pre-morbid mRS score of one or two (P=0.04). There was no statistically significant difference between two groups in terms of stroke severity on presentation (P=0.06). The onset to needle time was significantly longer in patients with a language barrier (188 min vs 173 min, P=0.04). Onset to arrival and door to imaging times were surprisingly similar between the two groups. However, imaging to needle time was 9 minutes delayed in non-English speaking patients with a marginal P value (65 vs 56 min, P=0.06). patients with language barriers stayed longer in stroke unit stay (6 vs 4 days, P=0.02) and had higher rates of discharge to residential aged care facilities in those admitted from home (9.2% vs 2.3%, P=0.02). In-hospital mortality was not different between two groups (P=0.8) CONCLUSION: In this study language barriers were associated with almost 14 min delay in thrombolysis. The delay was mostly attributable to imaging to needle time. Language barriers were also associated with poorer clinical outcomes.