B.I.H. or Pseudotumor is rare in children particularly under the first year of age. In addition, the syndrome at this age presents some peculiarities as compared with the adult form. This report describes the authors' experience with patients aged 4 to 12 months. Bulging fontanelle was the presenting symptom in all. Papilledema, strabismus, were present only in 1 case and vomiting in 4. Treatment was limited to lumbar puncture which was initially performed to rule out an acute CSN inflammatory process. In 8 patients the syndrome was precipitated by medications (sulfenazone - nalidixic acid); 3 had a prior history of 3 days of fever and roseola infantum, in 2 cases precipitanting factors were not found. Since the prompt remission of the intracranial hypertension (24 to 96 hours) neuroradiological investigations were not performed.