A case is reported of a 16-month-old girl who presented with generalized hypotonia, ptosis and persistent low grade fever after a previous pneumonia. Brain CT and MRI showed symmetric necrotizing lesions in the basal ganglia, substantia nigra and periaqueduct area. Lactate and pyruvate levels were elevated in both the blood and cerebrospinal fluid. Biopsy of the rectus femoris muscle for electron microscopic examination revealed some distortion of the mitochondrial cristae. Biochemical study showed normal respiratory chain enzymes. Leigh disease was considered from the neuroradiological findings and morphological investigations.