A case of ovarian teratoma which produced glial peritoneal deposits is described. Twelve other cases in the literature are tabulated. The age at presentation ranges from 22 months to 22 years (mean age 14·6 years). The primary tumour may be solid or cystic. The prognosis does not appear to be improved by radical surgery as opposed to simple excision but depends mainly on the maturity of the tissues of the primary tumour and the peritoneal deposits. Although the period of follow up is generally short, a survival time up to 26 years is recorded. In the fatal cases, there is rapid recurrence and metastatic spread. The pathogenesis of the glial deposits is discussed.