Abstract
We describe a 7-y-old boy who developed idiopathic intracranial hypertension (IIH) during the convalescent phase of Mycoplasma pneumoniae (M. pneumoniae) infection. Anti-M. pneumoniae antibody and cold hemagglutinin titer were extremely high during his course, and corticosteroid administration was noticeably effective. It supports an immunopathological mechanism for his intracranial hypertension.