Results of CSF examinations from 117 high-risk neonates were reviewed. The mean CSF cell count was 8.4 cells/mm3 and the range was 0 to 32 cells/mm.3 Approximately 60% of the CSF WBC were polymorphonuclear leukocytes. Average CSF protein concentrations were 90 mg/dl (range, 20-170 mg/dl) in term and 115 mg/dl (range, 65-150 mg/dl) in preterm infants. The average CSF glucose was 81% of the blood glucose value in term and 74% in preterm infants. Comparison of these CSF findings with those from 119 infants with bacterial meningitis revealed that there was considerable overlapping of values, but only one of the 119 infants with meningitis had a completely normal initial CSF examination. The decision to initiate antimicrobial therapy in neonates with suspected meningitis must be based on total evaluation of the patient.