A detailed history, physical examination and neurological examination are the basis of diagnosis. It is important to carefully understand the history, especially the onset, form, duration, concomitant symptoms, evolution and possible precipitating factors; to pay attention to various vascular risk factors; and to focus on the examination of cerebral nerves (vision, eye movements, facial sensation, hearing, vestibular function) and ataxia. In those with dizziness/vertigo as the main complaint, be sure to perform Dix-Hallpike examination to exclude benign episodic positional vertigo. Neuroimaging, mainly MRI, should be performed in all patients with suspected posterior circulation ischemia. DWI is most diagnostic for acute lesions. Cranial CT examination is susceptible to bone artifacts and has little diagnostic value, and is only applicable to exclude hemorrhage and patients who cannot enter MRI examination. Digital subtraction angiography, CT angiography, MRI angiography and vascular Doppler ultrasonography should be actively carried out to help detect and clarify large intracranial and extracranial vascular lesions. Each examination has its own characteristics, and there is a lack of correlation studies between different examinations. Transcranial Doppler ultrasonography (TCD) can detect stenosis or occlusion of the vertebral artery, but it cannot be the only basis for the diagnosis of posterior circulation ischemia. A variety of cardiac examinations can help to clarify embolism from the heart or aortic arch. Imaging of the cervical spine is not a preferred or important test.