Over an 18-month period, 511 patients with ischemic stroke were admitted to our hospital; 18 were treated with intravenous recombinant tissue plasminogen activator (rt-PA, alteplase 0.6mg/Kg). After rt-PA treatment, symptomatic intracranial hemorrhages (SIH) developed in 5 patients (age range, 58-85 years; time to treatment, 84-175 minutes; baseline NIHSS, 16-21); 3 had a hemorrhagic infarction; 1 had an intracranial hematoma; and 1 had a subarachnoid hemorrhage. Development of SIH related to NIHSS and antithrombotic medications. Three months after onset, their modified Rankin scale (mRS) scores were 2 in 1 patient and 5 in 4 patients. One patient had a cardioembolic stroke (CE) in the middle cerebral artery (MCA) territory that did not affect the perforating area and recovered functionally (mRS, 2), while 2 patients who had a CE in the entire MCA territory became bedridden (mRS, 5). In 2 patients not treated with anticoagulants, the hemorrhagic infarction kept enlarging until 2 weeks. In one patient who developed a subarachnoid hemorrhage after rt-PA, no aneurysms had been noted on MR angiography at the time of arrival. In conclusion, the risks and benefits of rt-PA need to be carefully considered in stroke patients, especially, those with severe neurological deficits.