Clinicians working in any acute medical/surgical unit need an understanding of mesenteric ischaemia. Acute mesenteric ischaemia is a life-threatening vascular emergency associated with high morbidity and mortality. However, prompt diagnosis with the use of contrast-enhanced CT, more specifically CT angiography, has replaced catheter angiography as the new standard and is readily available in many emergency departments. Similarly, new hybrid open surgery endovascular treatment can minimise the surgical insult to these often critically ill elderly patients. Together, these changes can change the previously grim prognosis associated with this condition. By contrast, chronic mesenteric ischaemia (CMI) is an insidious disease and often a diagnosis of exclusion. However, it can cause a significant reduction in a patient's quality of life, due to 'mesenteric angina' and food avoidance, yet can potentially be treated simply and effectively. Recognition of the typical clinical history and imaging findings is key to making the diagnosis in a timely fashion. Radiology plays a significant role in the diagnosis and increasingly in the treatment of mesenteric ischaemia. Other clinicians should have a basic understanding of what radiology can and cannot offer. The advantages and limitations of commonly used imaging modalities-plain films, CT, MRI and ultrasound, are examined. The significance of findings, such as pneumatosis coli and portal gas are explained. Finally, the different endovascular management of both acute and CMI is discussed, which have emerged as minimally invasive options to complement open revascularisation surgery.