Vanishing white matter disease is a newly recognised leukoencephalopathy of identified genetic background, characterised by cystic degeneration and progressive vanishing of white matter. The characteristic clinical symptoms are spasticity and ataxia with relatively preserved cognitive functions. A characteristic feature of the disease is the occurrence of the symptoms after a physical stress situation such as mild head trauma or febrile infection. We would like to present a case of a 6-year-old girl whose first symptoms of the disease occurred after being frightened by a horse.