This report describes a 49-year-old woman diagnosed as idiopathic hypertrophic pachymeningitis (IHCPM) with imaging evidence of diffuse dural sinus thrombosis. Over the years, secondary to the raised intracranial pressure, she had developed an anterior basal encephalocele through the defects in the cribriform plate of the ethmoid bone. The relation between elevated intracranial pressure and encephalocele is discussed.