Recent studies have shown that low radiation doses typical of those in medical imaging may induce malignancies. This creates a need for safe use of radiation during medical exposure. To promote safe radiation use, the Bonn call for action (2012) recommends the development of dose guidance levels for common radiological procedures. In spite the fact that benefits of dose guidance levels are well documented, the current policy of clinical practice in radiology and imaging in Uganda lack dose guidance levels for postero-anterior chest x-ray examination. Chest x-rays account for over 50% of all plain radiography examination done in radiology department. This study aimed at estimating the average entrance surface and effective dose received by adults undergoing postero-anterior chest x-ray examination.