The 2025 Tri-Society Cardiac & Thoracic Symposium (3SCTS) is a combined scientific meeting of three Australasian cardiothoracic societies: anaesthesia (ANZCA), surgery (ANZCTS), and perfusion (ANZCP). This will be the second 3SCTS meeting with the theme of “Collaborating in cardiothoracic care: A deep dive, down under”.