['To audit the efficacy of a conservative prophylactic antibiotic policy in patients undergoing non-trauma cranial surgery.', 'Prospectively collected infection data in consecutive patients who underwent non-trauma cranial surgeries in one neurosurgical unit between 1 January 2003 and 31 December 2011 were reviewed. Depending on the surgery performed, a one-day course of intravenous chloramphenicol or a single dose of ceftriaxone was used as the prophylactic antibiotic therapy. Patients with clinical and CSF features suggestive of meningitis were considered to have postoperative meningitis if the CSF culture was positive.', 'Bacterial meningitis was diagnosed in 27 (0.8%) of 3401 patients included in the study. Multidrug-resistant (MDR, organisms that were resistant to two or more first line of antibiotics) organisms were grown from CSF in four patients with bacterial meningitis (0.1%). There were two deaths among the 27 patients with successful treatment of meningitis in the other 25 patients.'] Does conservative antibiotic policy in patients undergoing non-trauma cranial surgery result in higher rates of postoperative meningitis : an audit of nine years of narrow-spectrum prophylaxis?