Acute childhood ataxia is a relatively common presenting complaint in paediatric emergency settings. Because life-threatening causes of pure ataxia are rare in children, an approach in a stepwise fashion is recommended. Acute cerebellar ataxia is the most common cause of childhood ataxia, accounting for about 30-50% of all cases. Varicella is the most commonly associated virus. Post-varicella acute cerebellar ataxia (PVACA) is the most common neurological complication of varicella, occurring about once in 4000 varicella cases among children younger than 15 years of age, even in the postvaccine era. We describe an unimmunised child with PVACA to remind emergency physicians about its autoimmune pathogenesis. We also briefly discuss current controversies about the diagnostic approach and management.