Background <p>Beta thalassemia major (β-TM) is a severe genetic anemia with considerable phenotypic heterogeneity. This study investigated whether genotype correlates with distinct myocardial iron overload patterns, assessed by cardiovascular magnetic resonance (CMR) T2* values.</p> Methods <p>CMR data for cardiac iron deposition evaluation, which recruited pediatric participants between January 2021 and December 2024, were analyzed with CVI42. The patients were classified into three genetic subgroups of β⁰/β⁰, β⁰/β⁺, and β⁺/β⁺ based on their genetic outcomes. The CMR results classified patients into normal myocardial T2* value and myocardial iron overload groups. Qualitative and quantitative factors were subsequently compared by groups using comparative statistics.</p> Results <p>The study included 145 pediatric β-TM patients, with 24 (17%) exhibiting cardiac iron deposition based on CMR T2* values. There were significant differences in iron chelation treatment strategies across genotypes, with the β⁰/β⁰ genotype accounting for 54% (13/24) of patients in the cardiac iron deposition group. Regardless of genotype, the mid-inferolateral segment consistently showed the lowest CMR T2* values and the highest prevalence of iron deposition.</p> Conclusion <p>The risk of cardiac iron deposition increases as age progresses, and the mid-inferolateral segment is more susceptible to iron accumulation. The β⁰/β⁰ genotype is more likely to suffer from cardiac iron overload, emphasizing the need for closer clinical monitoring and regular cardiac MRI evaluations.</p>