Context: Basilar artery occlusion(BAO) is an infrequent disease with high morbidity and mortality. Intra-arterial thrombolysis is advocated for treatment but is limited to use at specialized centers. Objective: To evaluate outcomes for patients with BAO treated with intravenous thrombolytic therapy. Design, Setting, and Participants: During 1995 to 2003, 50 consecutive patients with angiographically proven BAO were treated according to an institutional therapy protocol based on intravenous thrombolysis with recombinant tissue plasminogen activator(alteplase). Patients were treated at an urban university teaching hospital receiving all patients with ischemic stroke who were considered for thrombolysis in a catchment area of 1.5 million inhabitants in Helsinki, Finland. Intervention: Intravenous administration of alteplase(0.9 mg/kg) during a 1-hour infusion. Main Outcome Measures: Basilar artery recanalization determined by magnetic resonance angiography and clinical outcomes at 3 months and at 1 year or longer determined by modified Rankin Scale and Barthel Index scores. Results: Recanalization was studied in 43 patients and verified in 26(52%) of all patients. By 3 months, 20 patients(40%) had died while 11 had good outcomes(modified Rankin Scale score, 0-2); 12(24%) reached independence in activities of daily living(Barthel Index score, 95-100), and 6(16%) were severely disabled(Barthel Index score, 0-50). In the long term(median follow-up 2.8 years), 15 patients(30%) reached good outcomes(modified Rankin Scale score, 0-2) while 23(46%) died. Conclusions: Intravenous administration of alteplase for patients with BAO appears to be associated with rates of survival, recanalization, and independent functional outcome comparable with those reported with endovascular approaches. These data suggest that a randomized trial is needed to compare these approaches for treatment of BAO. Context: Basilar artery occlusion (BAO) is an infrequent disease with high morbidity and mortality. Intra-arterial thrombolysis is advocated for treatment but is limited to use at specialized centers. Objective: To evaluate outcomes for patients with BAO treated with intravenous thrombolytic therapy. Design, Setting, and Participants: During the period from 1995 to 2003, 50 consecutive patients with angiographically proven BAO were treated according to an institutional therapy protocol based on intravenous thrombolysis with recombinant tissue plasminogen activator (alteplase). Patients were treated at an urban university teaching hospital receiving all patients with ischemic stroke who were considered for thrombolysis in a catchment area of ​​1.5 million inhabitants in Helsinki, Finland. Intervention: Intravenous administration of alteplase (0.9 mg / kg) during a 1-hour infusion. Main Outcome Measures: Basilar artery recanalization determined by magnetic resonance angiography and clinical outcomes at 3 month Results: Recanalization was studied in 43 patients and verified in 26 (52%) of all patients. By 3 months, 20 patients (40%) had died while 11 had good outcomes (modified Rankin Scale score, 0-2); 12 (24%) reached independence in activities of daily living (Barthel Index score, 95-100), and 6 (16%) were severely disabled disabled Conclusions: Intravenous administration (median follow-up 2.8 years), 15 patients (30%) reached good outcomes (modified Rankin Scale score, 0-2) while 23 (46%) died. of alteplase for patients with BAO appears to be associated with rates of survival, recanalization, and independent functional outcome comparable with those reported with endovascular approaches. These data suggest that a randomized trial is needed to compare these approaches for treatment of BAO.