Background and Purpose: It is unclear whether prior therapy with antiplatelet agents (APA) is associated with a better outcome in patients with acute ischemic cerebrovascular events. Methods: Within a multi- center cross- sectional study, nested in a cohort we analyzed the relation between prior therapy with APA and stroke severity in 1643 patients with acute ischemic stroke or TIA. Clinical severity of the vascular event was evaluated by the National Institutes of Health Stroke Scale on admission (NIHSS1) and after 1 week (NIHSS2). By means of analysis of variance we analyzed a possible association of APA with stroke severity and interactions regarding stroke severity between APA and other clinical measures. Results: 475 patients (29 % ) received aspirin prior to the cerebrovascular event, 51 patients (3 % ) ticlopidine or clopidogrel and 26 patients (1.6% ) aspirin combined with extended release dipyridamole. 66% (1091) of patients did not take any antiplatelet medication. Neither the NIHSS1 nor the NIHSS2 nor the change of stroke severity between these time points (NIHSS1- NIHSS2) was associated with prior APA medication. We did not find significant interactions between APA use and clinical measures regarding stroke severity. Conclusions: Our results do not indicate that prior therapy with APA is associated with a better outcome in acute ischemic cerebrovascular events. There were no interactions found with other features that were associated with stroke severity. Background and Purpose: It is unclear whether prior therapy with antiplatelet agents (APA) is associated with a better outcome in patients with acute ischemic cerebrovascular events. Methods: Within a multi- center cross- sectional study, nested in a cohort between prior therapy with APA and stroke severity in 1643 patients with acute ischemic stroke or TIA. Clinical severity of the vascular event was evaluated by the National Institutes of Health Stroke Scale on admission (NIHSS1) and after 1 week (NIHSS2). By means of analysis of variance we analyzed a possible association of APA with stroke severity and interactions versus stroke severity between APA and other clinical measures. Results: 475 patients (29%) received aspirin prior to the cerebrovascular event, 51 patients (3%) ticlopidine or clopidogrel and 26 patients (1.6%) aspirin combined with extended release dipyridamole. 66% (1091) of patients did not take any antiplatelet e NIHSS1 nor the change in stroke severity between these time points (NIHSS1-NIHSS2) was associated with prior APA medication. We did not find significant interactions between APA use and clinical measures regarding stroke severity. Conclusions: Our results do not indicate on stroke time that prior therapy with APA is associated with a better outcome in acute ischemic cerebrovascular events. There were no interactions found with with other features that were associated with stroke severity.