Twenty per cent of cerebral ischaemic infarctions involve tissue, supplied by the vertebrobasilar circulation. This overview of the current literature and our own experiences present the value of different imaging techniques (CT and MRI) and new developments for diagnosing brainstem infarction. Furthermore, the roles of invasive and noninvasive vascular imaging methods (computed tomographic angiography, magnetic resonance angiography, intra-arterial angiography, ultrasound) for evaluating vertebrobasilar stenosis and occlusion are described. The diagnostic workup of the most severe form of brainstem infarction, basilar artery thrombosis, is shown.