We report an unusual case of a 17-year-old young female presenting to the emergency department with varicella infection, acute urinary retention (AUR) and no other neurological deficits. An MRI of the spine confirmed the diagnosis of acute transverse myelitis. Positive serum IgG antibodies against varicella zoster virus (VZV) suggested a parainfectious aetiology. The patient eventually developed weakness and a sensory level from the third thoracic dermatome on day 2 of hospitalisation. Awareness that AUR can precede other neurological deficits in VZV transverse myelitis will prevent misdiagnosis and allow for the prompt treatment of this debilitating illness.