Objective To investigate the clinical characteristics of stroke warning syndrome (SWS) and to explore the effectiveness of intravenous thrombolysis with alteplase. Methods Eleven patients with SWS, who received intravenous thrombolysis with alteplase in Stroke Center of our hospital between Sep. 2013 and Jan. 2018, were selected. The clinical features, imaging findings and therapeutic effects were analyzed. Results There were risk factors of cerebrovascular diseases in the 11 patients with SWS, in which 7 had hypertension, 4 had diabetes mellitus, 2 had hyperlipoidemia, and 1 had gout. In the classification of symptoms, 7 patients were pure motor type and 4 were motor-sense type. Magnetic resonance diffusion weighted imaging showed that 10 patients developed ischemic stroke. The infarction located in the posterior limb of internal capsule, putamen, globus pallidus, corona and pons. Head and neck computed tomography angiography examination found no large vascular stenosis in the patients. The modified Rankin scale scored 0-1 in 9 patients, 2 in 1 patient, and 3 in 1 patient. Conclusion Perforating artery disease is the main pathogenesis of SWS. Intravenous thrombolysis does not prevent SWS to ischemic stroke, but it improves the prognosis of the patients.