We report a new case of pathologically documented Joubert syndrome. A review of 35 published cases showed that this syndrome, first described by Joubert and Eisenring in 1969, is well individualized and exhibits consistent features, including attacks of tachypnea alternating with respiratory pauses, abnormal ocular movements, severe psychomotor retardation, and ataxia. Anatomic anomalies include vermian agenesis with cystic dilatation of the fourth ventricle. Inheritance of this condition is autosomal and recessive. Onset is in the neonatal period and prognosis is severe. Significant anatomic resemblances with the Dandy-Walker syndrome exist, although genetic and clinical features are different. The origin of this syndrome is unknown, but a study of peroxisomes is required since three cases of Joubert syndrome with pipecolic acidemia have been reported and resemblances exist between some recognized peroxisomal diseases and Joubert syndrome.