Background: Thalassemic patients' survival is closely linked to the quality of blood transfusion and iron chelation therapy. Non-adherence to chelation therapy severely compromises patient health, quality of life and survival. Aim of the study: Was to evaluate the effect of multidimensional intervention on improving adherence of thalassemic children to iron chelation therapy. Subject and method: Research design: A quasi experimental (pre-post) design was used. Setting: Pediatric Hematology Outpatient Clinic at Zagazig University Hospital, Zagazig, Egypt. Subjects: A purposive sample of 50 thalassemic children. Tools of data collection: Three tools were used to collect the necessary data included; a structured interview questionnaire, Morisky 8-Item Medication Adherence Scale (MMAS-8), and Chelation Therapy Management Form. Results: It was found that thalassemic children' adherence to iron chelation therapy and their serum ferritin levels were significantly improved after implementation of the multidimensional intervention (P=0.001). Conclusion: The multidimensional intervention improved thalassemic children' adherence to iron chelation therapy. Recommendations: multifaceted/ multidimensional interventions tailored to individual patients' needs, will be helpful in managing medication adherence issues