Veno-arterial extracorporeal membrane oxygenation (VA ECMO) fundamentally alters patient physiology and blood flow relevant to contrast delivery for computed tomography (CT) imaging. Here, we present a comprehensive guide to contrast-enhanced CT scanning in adult ECMO patients, addressing common questions related to contrast delivery via the ECMO circuit, and modifications to ECMO settings and scanning techniques, to avoid non-diagnostic CT scans. The approach is described in detail for patients supported on VA ECMO, with the return cannula sited in the femoral artery. Lesser modifications required for veno-venous ECMO (VV ECMO) are included in the supplemental material. Establishing a common understanding between the intensive care clinician, the CT radiographer, and the radiologist, concerning the patient’s blood-flow-physiology, is the overarching goal. Our stepwise approach facilitates clear communication around modifications to the ECMO pump settings, contrast route and rate, as well as the scanning technique, for each individual scenario.