Forty-six cases of basilar skull fractures in children were reviewed to determine the incidence of CNS infection following injury and the possible value of antimicrobial chemoprophylaxis. The clinical course of the children who were treated with antibiotics was compared with that of patients who received no antimicrobial therapy. Included in the study were patients with hemotympanum alone or with hemotympanum plus additional clinical or roentgenographic signs of basilar skull fracture; patients with tympanic membrane perforation without otorrhea but with blood in the auditory canal; and children with either otorrhea or rhinorrhea. Acute, delayed, or recurrent infection of the CNS did not develop in any of the patients. This study is the first of its kind presented in children. It would seem on the basis of the present series that the systematic use of antibiotic prophylaxis in children with hemotympanum following basilar skull fractures is unwarranted and that children with other signs of basilar skull fractures may have an equally small risk of meningitis following injury.