B AC K G R O U N D We aimed to determine the value of perfusion computed tom o graphy (CT) in pat ients with acute isch em i c stroke and compare the results with magnetic resonance imaging (MRI) and late CT findings. M ET H O D S Each patient first underwent nonenhanced CT scans of the brain to exclude hemorrhage. Perfusion CT was performed within less than 12 hours of symptom onset in 32 patients (21 men, 11 women) whose CT findings were suspicious or normal. R E S U LT S Perfus ion CT showed abn o rm al it ies at the 20 different arter ial terr it or ies of 14 pat ients (43.7%) with a sens itivity of 93.3% and spec if icity of 100%. Cer e bral blood flow c h a nges were found red uced sev erely in 4 and mod erately in 11 of the 20 terr it or ies. Cerebral blood vol um e c h a nges were det e cted sev erely red uced in 4 and mod erately red uced 10 terr it or ies. TTP was del ayed sev erely in 4 and mod erately in 11 terr it or ies. CO N C L U S I O N S CT maintains its preeminent role in the evaluation of patients with symptoms suggestive of acute stroke. CT perfusion has significantly augmented the role of CT for the patients offering valuable information critical in management of acute stroke.