Background: Brain-specific glial fibrillary acidic protein (GFAP) can discriminate stroke type [ischemic stroke (AIS), intracerebral hemorrhage (ICH), stroke mimics (SM)]. Novel point-of-care technology (GFAP levels <15 minutes) is a promising diagnostic tool. We aim to evaluate the feasibility of rapid GFAP analysis in acute stroke. Methods: Exploratory analysis of an ongoing prospective study of suspected undifferentiated stroke <24h from onset. Rapid plasma GFAP levels (pg/mL) are measured at hospital arrival using the i-STAT Alinity® instrument and commercially-available cartridges. Study endpoints include quantitative GFAP levels according to final diagnosis and time from stroke onset. Results: Among 200 patients (mean(±SD) 70.7±15.5 years, 44.5% female, median (IQR) NIHSS 9(4-19), diagnosis was AIS (n=132 (59 large-vessel occlusion), ICH (n=17), and SM (n=51). Median time from hospital arrival to GFAP result was 56.0 (47.0-69.5) minutes. Median rapid GFAP levels were highest in ICH (878.0 (70.5-3,906.5) pg/mL) compared to AIS (49.5 (29.0-95)pg/mL) and SM (29(29-64)pg/mL), p=0.001. Median GFAP was higher in AIS-known onset >4.5h (n=9) (110.0 (44.0-216.0) pg/mL) compared to AIS<4.5h (40.5 (29.0-68.8) pg/mL) (n=72), (p=0.047), while AIS-unknown onset (n=51) (68.0 (29.0-108.5) pg/mL) fell between these two groups, likely reflecting the subgroup’s heterogeneity. Conclusions: Preliminary findings suggest that rapid GFAP analysis is feasible in acute stroke and may inform treatment decisions.