Background: Magnetic resonance T2-star (T2* MRI) imaging is non-invasive and reliable method to evaluate myocardial iron content in patients with beta thalassemia major. This study aimed to determine cardiac iron load of thalassemia major patients using T2* MRI and to detect its relation to clinical characteristics, genotype and serum ferritin level. Methods: Cross sectional study was carried on 100 patients with beta thalassemia in the period between May 2017 to April 2019. MRI heart and liver was done to detect myocardial and hepatic iron overload. Genotyping was done by using DNA sequencing method. Results: The mean cardiac T2* was 28.2 ms and mean liver iron content was 14.4 mg/g dw. Patients with β0β0 genotype had significantly higher myocardial iron load compared to those with β0β+ and β+β+ genotypes. Myocardial iron overload was strongly correlated to liver iron content and serum ferritin level. Conclusion: Myocardial iron overload was a significant problem in patients with beta thalassemia major with a clear association with genotype, liver iron content and serum ferritin level