Joubert's sundrome is a rare cerebellar malformation belonging to the group of rhom-boencephaloschisis and characterised by varying degrees of hypoplasia of the cerebellar vermis or complete agenesis. We describe an infant referred to us at six months of age for oculomotor apraxia and delayed psychomotor development. We focus on the neuroradiological features essential to diagnosis of Joubert's syndrome. The absence of hyperpnea in the neonatal period and prematurity deemed responsible for initial episodes of central apneas, prevented early diagnosis.