BACKGROUND AND PURPOSE-: Early deterioration can occur after acute stroke for a variety of reasons. We describe a hemodynamic steal and associated neurological deterioration, the reversed Robin Hood syndrome (RRHS). We aimed to investigate the frequency and factors associated with RRHS. METHODS-: Consecutive patients with acute cerebral ischemia underwent serial National Institutes of Health Stroke Scale and bilateral transcranial Doppler monitoring with breathholding. Steal magnitude (%) was calculated from transient mean flow velocity reduction in the affected arteries at the time of velocity increase in normal vessels. Excessive sleepiness and likelihood of sleep apnea were evaluated by the Epworth Sleepiness Scale and Berlin Questionnaire. RESULTS-: Among 153 patients (age, 61±14 years; 48% women; 21% transient ischemic attack) admitted within 48 hours from symptom onset, 21 (14%) had steal phenomenon (median steal magnitude, 20%; interquartile range, 11%; range, 6% to 45%), and 11 (7%) had RRHS. RRHS was most frequent in patients with proximal arterial occlusions (17% versus 1%; P<0.001). The following factors were independently (P<0.05) associated with RRHS (multivariate logistic regression model): male gender, younger age, persisting arterial occlusions, and excessive sleepiness (P<0.001). A 1-point increase in the Epworth Sleepiness Scale was independently related to an increased likelihood of RRHS of 36% (95% CI, 7% to 73%). CONCLUSIONS-: RRHS and hemodynamic steal can be found in 7% and 14%, respectively, of consecutive patients with stroke without other known causes for deterioration. Patients with persisting arterial occlusions and excessive sleepiness can be particularly vulnerable to the steal. © 2009 American Heart Association, Inc.