Objective: The purpose of this study was to assess oral health status in children with thalassemia major, and the association of oral health status with oral-health related to quality of life. Methods: This cross-sectional study was comprised of 81 patients from various parts of lower northern Thailand. The study consisted of an interview and intraoral examination on thalassemia children at the hospital while they were undergoing routine blood transfusions. Data regarding OHI-S, DMFT/dmft and child-OIDP were determined for all the subjects. Results: The prevalence of oral impacts was high; 82.8% of all children reported at least one oral impact affecting their daily performance according to the Child-OIDP. The most prevalent impact was difficulty in eating. Conclusion:The risks of oral disease in thalassemia children remain high which affect their quality of life.