OBJECTIVE: Although some data regarding the use of thrombolysis are available from community-based studies, national estimates of the use of thrombolysis for ischemic stroke are not available. We performed this study to determine the frequency of thrombolysis for ischemic stroke in the United States and associated in-hospital outcomes. METHODS: National estimates of thrombolysis, associated in-hospital outcomes, and mortality were obtained from National Hospital Discharge Survey data from 1999 to 2001. Patient numbers and frequency distributions were calculated for a nationally representative sample of patients hospitalized with a primary diagnosis of ischemic stroke. Thrombolysis was further stratified into thrombolysis with (intra-arterial) or without (intravenous) cerebral angiography. RESULTS: There were 1,796,513 admissions for ischemic stroke between 1999 and 2001. Of these admitted patients, 1,314 (0.07%) underwent intra-arterial thrombolysis and 11,283 (0.6%) underwent intravenous thrombolysis. The days of hospitalization (mean +/- standard deviation) were significantly higher for patients admitted with ischemic stroke treated with intra-arterial thrombolysis (10.7 +/- 4.8) or intravenous thrombolysis (7.1 +/- 3.6) compared with non-thrombolytic admissions (5.4 +/- 5.7). We observed a trend toward a higher frequency of use of intravenous and intra-arterial thrombolysis and hospitals with greater number of beds (P < 0.01). The mortality rates for hospitalizations were not significantly different for admissions with ischemic stroke treated with intra-arterial or intravenous thrombolysis compared with other ischemic strokes. The rates of discharge to home after hospitalizations were significantly lower for patients treated with intravenous thrombolysis (19.8%) compared with those not treated with thrombolysis (53.1%). CONCLUSION: The present study provides national estimates of patients undergoing thrombolysis for ischemic stroke. Further efforts need to be made to increase the proportion of patients with ischemic stroke who receive thrombolysis in the United States.