Background: Multiple risk factors in Beta-thalassemia major (βTM) children contribute to the impairment of their neurocognitive function. Multiple studies used different intelligence quotient (IQ) scores to assess the neurocognitive function in thalassaemic children, however, results were variable. Objective: This study aimed to assess the cognitive functions of thalassemic children and to compare them to a well-matched group of healthy controls using the Fourth Edition of the Wechsler Intelligence Scale for Children (WISC- IV). Subjects and Methods: A cross-sectional study recruited two groups; Group I included 50 children diagnosed with βTM on regular blood transfusions. Group II included 50 healthy control children with no underlying chronic illness, matching the patients' age, sex, education, parent's education, school performance, and socioeconomic level. A detailed history was taken, and clinical examination was performed; also, laboratory investigations including full blood picture and serum ferritin were done. Neurocognitive functions were assessed using WISC- IV. Results: βTM children had significantly lower IQ scores on cognitive function assessment than healthy children, including the mean of the Full-Scale Intelligence Quotient, as well as the mean scores of the Verbal Comprehension Index, the Processing Speed Index, the Perceptual Reasoning Index, and the Working Memory Index (P<0.01). There was no correlation between IQ scores and the age at the onset of disease, transfusion frequency per year, serum ferritin, onset and duration of chelation, type of chelation, parents' education, and socioeconomic status. However, IQ scores were positively correlated with pretransfusion Hb, school performance, education, and anthropometric measurements. Conclusion: We concluded that βTM children have significantly lower IQ scores than healthy children, and this requires attention for neuropsychological assessment of thalassemic children early in life to provide adequate support.