Bilateral retinal dysfunction with optic atrophy was evident in a 26-year-old man along with renal, hepatic and cardiac dysfunction. MRI showed undersized cerebellar vermis. Blood lactate and pyruvate were high, indicating possible mitochondrial dysfunction. In biopsied biceps muscle, some ragged red fibers were identified. In five usually congenital or inherited syndromes, Dandy-Walker, Joubert, Arima, Dekaban and COACH, the symptoms such as hypoplasia or aplasia of the cerebellar vermis with multiple ocular and systemic disorders serve as the basis for differential diagnosis. The present case showed numerous symptomatic similarities and a few specific differences with Arima, Dekaban and COACH syndromes. These three syndromes and the present case were thus given a single designation, cerebello-oculo-hepato-renal syndrome, although the present case was an adult patient with sporadic onset. Some systemic disorders not included in cerebello-oculo-hepato-renal syndrome were also noted in our case and may possibly be explained by mitochondrial dysfunction, as indicated by blood pyruvate and lactate levels and the presence of ragged red fibers in biopsied biceps muscle. The relationship between cerebello-oculo-hepato-renal syndromes and mitochondrial dysfunction is discussed.