AIMS: (Equation is included in full-text article.)multislice multiecho cardiac magnetic resonance (CMR) allows quantification of the segmental distribution of myocardial iron overload (MIO). We evaluated whether a preferential pattern MIO was preserved between two CMR scans in regularly chelated thalassaemia major (TM) patients. METHODS AND RESULTS: We evaluated prospectively 259 TM patients enrolled in the MIO in Thalassaemia (MIOT) network with a CMR follow-up (FU) study at 18 ± 3 months and significant MIO at baseline. The (Equation is included in full-text article.)in the 16 segments and the global value were calculated. Four main circumferential regions (anterior, septal, inferior and lateral) were defined. We identified two groups: severe (n = 80, global (Equation is included in full-text article.)<10 ms) and mild–moderate MIO (n = 179, global (Equation is included in full-text article.)= 10–26 ms). Based on the CMR reports, 56.4% of patients changed the chelation regimen. For each group, there was a significant improvement in the global heart as well as in regional (Equation is included in full-text article.)values (P < 0.0001). At the baseline, the mean (Equation is included in full-text article.)value over the anterior region was significantly lower than the values over the other regions, and the mean (Equation is included in full-text article.)over the inferior region was significantly lower than the values over the septal and the lateral regions. The same pattern was present at the FU, with a little difference for patients with mild–moderate MIO. CONCLUSION: A preferential pattern of iron store in anterior and inferior regions was present at both CMRs, with an increment of (Equation is included in full-text article.)values at FU due to a baseline CMR-guided chelation therapy. The anterior region seems the region in which the iron accumulates first and is removed later.