Objective: This study aimed to evaluate the relationship between thalassemia disease and body mass index (BMI) and the correlation with blood group of thalassemia patients.Methods: The study includes 260 persons (male+female), 200 persons were thalassemia patient (120 male and 80 female), and 60 healthy persons (30 male and 30 female) as control group; furthermore, people were divided into three group according to age 1–9, 10–19, and >20 years, and BMI and blood group were measured for all patients and healthy people.Results: The results showed that the frequency of thalassemia in male (65%) is higher than in female (40%); as well as, the results showed that the age group (10–19) years is more frequent in male, while in female, the age group (1–9) years is more frequent. The results of BMI revealed a significant decrease (p<0.05) in all groups of thalassemia patients compared with healthy group; as well as, the results of blood group showed that the group (O+) is the more frequent 34% in comparison with the other blood groups.Conclusion: We conclude that there was a strong relationship among gender, blood group (the most common blood group observed is O +ve), and BMI with thalassemia.