Gliomatosis peritonei is the implantation of military glial tissue within the peritoneal cavity or omentum of patients with ovarian teratomas. Gliomatosis peritonei is usually associated with immature, or infrequently with mature, ovarian teratoma, Extensive sampling of all peritoneal implants is warranted in the diagnosis of gliomatosis peritonei. Thus, in the face of peritoneal implants suspected to be of a teratomatous nature, thorough and extensive sampling is essential to exclude the presence of immature elements which may imply a poor prognosis and require aggressive therapy.