Abstract Photon-counting detector computed tomography (PCD-CT) is the most recent advancement in CT technology and has the potential to change clinical practice. Unlike conventional energy-integrated-detector (EID) that uses a two-step process to convert X-rays into a digital signal, PCD-CT directly converts photon energies into electronic signal. The advantages of PCD-CT over EID-CT are higher spatial resolution, electronic noise reduction, higher contrast-to-noise ratio, improved radiation dose efficiency, and intrinsic spectral imaging. Successful implementation into clinical practice requires adaptations in CT protocols. In this review, we summarize the basic principles of PCD-CT and technical scanning factors followed by a discussion of its clinical benefits in pediatric pulmonary and cardiovascular imaging.