Medical imaging plays a crucial role in the diagnosis, staging, monitoring of response to therapy and longitudinally following patients after completion of therapy to detect recurrent disease, second cancers, and sequelae of therapy. Though vitally important, medical imaging is not without risks. The decisions of when, how, how frequently, and for whom surveillance imaging should be performed are complex. The balance of risks and benefits of imaging is particularly important in pediatric patients during periods of growth and development when adverse outcomes may impact their lifetime. This balance should be considered in the context of the critical benefit of medical imaging and not induce anxiety or promote avoidance of imaging that is necessary for the optimal care of the patient. This chapter is meant to provide health-care providers with an overview of potential risks associated with medical imaging and should not be considered the definitive source because medical imaging, available modalities, and techniques are constantly evolving.