Background: Stroke is the third most common cause of disability and second most common cause of death worldwide. Brainstem is involved in almost all the important functions of the central nervous system, and brainstem infarction is relatively dangerous with high mortality. Early prediction of the severity and degree of disability and identification of high-risk patients are critical for the treatment of patients with brain stem infarction and might contribute to reduce death rates and comorbidities after stroke. Objective: To assess the usefulness of Posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) for predicting functional outcome in posterior circulation stroke patients. Subjects and Methods: A cohort study on 61 patients with first-ever acute ischemic stroke who were admitted within 24 h from onset. Results: We observed a statistically significant correlation between poor outcome and high NIHSS score on initial assessment, as well as low pc-ASPECTS score, in contrast to other factors involved in the study such as, age, sex, hypertension, atrial fibrillation, diabetes mellitus, high lipid profile, smoking, time from onset to presentation, ESR, initial blood glucose measurement, HbA1C, leukoaraiosis, silent infarction or type of stroke. Conclusion: both the pc-ASPECTS and NIHSS help clinicians predict functional outcomes. The pc-ASPECTS is more reliable than the NIHSS in minor stroke prediction. Moreover, the combination of the pc-ASPECTS and NIHSS has an additive effect in predicting the functional outcomes of patients with posterior circulation stroke.