Abstract: Ionizing radiation used in medical imaging has probability to establish carcinogenesis and it is important to measure the radiation doses to critical organs of known sensitivity to the stochastic effects. Due to the small size of pediatrics’ body, the chest X-ray examinations are associated with high radiation exposure of non-relevant adjacent organs such as the thyroid gland. Since the thyroid cancer, particularly in pediatrics has been well established and the increasing risk of thyroid cancer from low levels of medical diagnostic X-rays has been highlighted, we aimed to measure the surface dose to the thyroid gland of pediatrics undergoing antero-posterior (AP) chest examination. After assessing each patient against specific inclusion-exclusion criteria, 100 pediatric patients who underwent AP chest X-ray examination were considered eligible for this study.