OBJECTIVES: Transfusional iron overload is common among patients with myelodysplastic syndromes (MDS) receiving red blood cell (RBC) transfusions. Emerging evidence indicates that iron chelation therapy (ICT) could improve health outcomes in MDS patients with low/intermediate-1 IPSS risk. This study aimed to investigate clinical evolution and transfusion dependency of MDS patients under ICT with deferasirox, in clinical practice. METHODS: This was a retrospective analysis of a hospital registry of MDS patients followed-up by imunohemotherapy. Longitudinal data records were aggregated in 3 months periods. Exploratory analysis was performed to characterize patients. Generalized Estimation Equation models were used to estimate the effect of time on average ferritin levels and RBC transfusions, controlled by patient’s initial conditions and deferasirox dose. Generalized Linear Mixed-effects Models were estimated to assess individualized evolution patterns. In modelling only patients chelated for ≥6 months were considered. RESULTS: A total of 877 records of 17 MDS patients (53% male), classified as low risk at diagnosis, were included in the analysis. Median ages at diagnosis, beginning of RBC transfusions and beginning of ICT were 71, 74 and 77, respectively. Patients had received an average of 51.6±26.2 RBC units before ICT. Average values of clinical parameters were calculated for each patient. Sample medians were: ferritin 3674.3ng/mL, hemoglobin 8.2g/dL, alkaline phosphatase 91.3UI/L, gamma-glutamyl transferase 0.4UI/L, aspartate aminotransferase 27.0UI/L, alanine aminotransferase 42.9UI/L and blood creatinine 0.9mg/dL. From the 8 patients chelated ≥6 months: 6 presented a decrease on ferritin levels and 4 presented a decrease in RBC transfusions (one reaching transfusional independence), over time. Marginal models demonstrated that average ferritin levels and number of RBC decrease with time (β=-141.9 p=0.008; β=-0.043 p=0.001, respectively). CONCLUSIONS: Analysis of real-world data from a Portuguese registry of transfusion-dependent MDS patients chelated with deferasiforx, for ≥6month, indicated that both ferritin levels and RBC transfusions tend to decrease with time.