In recent years, the volume of diagnostic procedures involving the use of ionizing radiation has rapidly increased. Technological advances in computed tomography (CT) equipment, with the availability of multi-slice acquisition and the introduction of hybrid systems, have made this modality extremely popular among other diagnostic procedures, especially in pediatrics and as a screening procedure for asymptomatic adults. Physicians' major radiation-related concern regarding diagnostic imaging, is possible iatrogenic malignancy. According to major national and international organizations responsible for evaluating radiation risks, there is no low-radiation threshold for inducing cancer. This means that no amount of radiation should be considered absolutely safe. Although, the risk of radiation-induced cancer is much smaller than the risk of cancer from natural sources, it can become a public health concern if large numbers of the population undergo increased numbers of CT screening procedures that may even be of uncertain benefit. In order to reduce the overall radiation dose from CT procedures in the population, it is important to keep radiation dose as low as reasonably achievable, by adjusting scanner parameters separately for each individual. In addition, it is crucial to eliminate the inappropriate referrals for CT tests and choose other diagnostic modalities, such as sonography, magnetic resonance imaging systems, or nuclear medicine procedures. While CT remains an important diagnostic procedure, it is important for health care community to reconsider the indications of a CT scan, especially in children and asymptomatic patients. Physicians who prescribe CT could assess its use on a case-by-case basis. When used prudently and optimally, CT remains a very valuable imaging modalitiy for both children and adults.