Background: β-Thalassemia is a hereditary disease. The traditional method of treatment is blood transfusion and iron chelation therapy that may associated with many psychological complications. The aim of our study is to assess the intelligence quotient in patients with transfusion dependent and non-transfusion dependent βthalassemia. Patients and methods: This study included 36 patients with transfusiondependent thalassemia, 19 patients with non-transfusion-dependent thalassemia and 37 healthy subjects as a control group. Routine laboratory investigations were done for thalassemic patients according to international standards. Neuropsychologically tests were performed. Results: There is statistically significant difference between the studied groups regarding IQ score. On LSD comparison, the difference is significant between TDT and each of non-TDT and control groups where the lowest IQ prevailed in TDT group. There is statistically significant difference between the studied groups regarding IQ score. Low score presented only in TDT group (47.2%). High average occurred in 11.1% of non-TDT group and 13.9% of control group. Average score was present in 44.4%, 75% and 63.9% of those within TDT, non-TDT and control groups respectively. There is statistically significant difference between the studied groups regarding duration of transfusion (higher in non-TDT group).Conclusion: There is a difference in intelligence quotient and the degree cognitive affection between transfusion-dependent and non-transfusion-dependent β-thalassemia patients. Thus, IQ should be routinely assessed in B-thalassemia major patients for early detection of intellectual impairment and allow for appropriate management, in order to achieve a better life quality for this patients group.