Results of cerebrospinal fluid (CSF) examinations from 77 high-risk neonates were reviewed. The mean CSF white cells (WBC) count was 4.5 cell/mm3, being two standard deviations above the mean 11.7 cells/mm3 in the full-term gestation neonate group; in the premature neonate one, the mean CSF WBC count was 5.1 cells/mm3, being two standard deviations above the mean 16.7 cell/mm3. PMNs (polymorphonuclear leukocytes) were present in less than 40% of those children, being the mean PMN percentage 4.2% and 0.6%, the mean ANC (absolute neutrophil count) was 0.3/mm3 and 0.06/mm3, in full-term gestation neonate group and premature neonate one, respectively. The mean CSF protein concentration is significantly greater in those premature neonates (101.2 mg/dl) compared with that in term neonates (77.6 mg/dl). The average glucose was just the same in both groups (67 mg/dl). All of these values were from patients who underwent nontraumatic cisternal puncture, with no red blood cells (RBC/mm3 = 0). Traumatic puncture, even up to 500 RBC/mm3, interfered on CSF parameters.