Photon-counting CT (PCCT) represents a transformative advancement in cardiac imaging, addressing key limitations of conventional CT. This review synthesises current evidence to demonstrate how PCCT’s superior spatial resolution, enhanced tissue characterisation and multienergy capabilities broaden the diagnostic potential of cardiac CT. Applications include the precise detection and quantification of coronary artery calcifications, evaluation of coronary plaque burden and composition, improved assessment of coronary stents, and comprehensive myocardial tissue characterisation and perfusion analysis. By offering high-quality spectral information and detailed tissue characterisation, PCCT provides a non-invasive alternative for assessing coronary artery disease and myocardial pathology, reducing the need for invasive coronary angiography and cardiac MRI. Despite ongoing challenges in technology and clinical implementation, PCCT has the potential to revolutionise cardiovascular diagnostics, optimise diagnostic workflows and enhance patient care through more accurate, streamlined and comprehensive assessments.