Enoyl-CoA hydratase short-chain 1 (ECHS1) variants are among the most common causes of Leigh syndrome. A five-year-old boy with ECHS1 deficiency initially presented with acute encephalopathy during the neonatal period. The patient had a high serum lactate level and a normal lactate/pyruvate ratio. Diffusion-weighted imaging showed reduced diffusion in the peri-rolandic subcortical white matter on day 3 and in the entire cortex and subcortical white matter on day 7. The patient subsequently presented with poor feeding, hypotonia, nystagmus, cerebellar ataxia, hearing loss, and strabismus. At one year of age, neuroimaging revealed reduced diffusion, hyperperfusion on arterial spin labeling, and increased lactate on magnetic resonance (MR) spectroscopy in the cerebellum. Cerebellar lesions have not previously been reported as imaging findings of ECHS1 deficiency except in one previous report of a patient with the same ECHS1 variant. Therefore, the ECHS1variant may specifically involve the cerebellum.