X-rays are form of ionization radiation used to create images that help with patients'' diagnosis in diagnostic radiology. Ionisation radiation may potentially damage cells within the body. A dose measurement must be done to avoid unnecessary radiation to patients during X-ray imaging. This textbook explains the importance of diagnostic reference levels (DRL''s) and the development of DRL''s which was achieved by assessing the dose received by patients in radiographic exposures at the Dr George Mukhari hospital. Different X-ray techniques were used to estimate the entrance surface dose using TLD''s placed on the Rando phantom.