Diagnosing ischaemic stroke in children is often difficult. Post-varicella angiopathy (PVA) is a well-recognised and frequent cause of childhood ischaemic stroke, particularly affecting the basal ganglia. When a previously healthy child presents with unilateral abnormal involuntary movements, cerebral infarction should be included in the differential diagnosis and PVA should be considered, even when there is no recent history of rash and cerebrospinal fluid is normal. Medical history and intracranial vascular imaging are important for early diagnosis and treatment.