Lateral Cerebral Ventricular Asymmetry (LCVA), a qualitative estimate of lateral cerebral ventricular size difference, has been previously described in neonatal head ultrasound studies. However, the clinical conditions associated with this finding are unknown. In order to investigate the risk factors associated with LCVA we retrospectively reviewed all infants < 1500 grams admitted to the Medical Center of Delaware over a period of 24 months(7/93-7/95). All infants who received a minimum of one head ultrasound were included in the analysis, n=221. All head ultrasounds were reviewed by a pediatric radiologist. Overall, 18 (8%) of the study population was reported to have LCVA. Univariate analysis was performed using Student's t-test or Chi-square. Multivariate analysis was then performed using significant variables. The neonates with LCVA, as compared to those without LCVA, more often had: grade III-IV intraventricular hemorrhage [IVH] (27.8% v. 8.9%, p<.03) and bronchopulmonary dysplasia (66.7% v. 42.6%, p<.05). There was no difference in: birth weight, gestational age, gender, grade I-II IVH, cystic PVL, hydrocephalus, seizures, caffeine, theophylline, maternal age, maternal drug use, magnesium sulfate, steroids, preeclampsia, sepsis, NEC, PDA, surfactant, dopamine, number of red blood cell or platelet transfusions. Multivariate forward stepwise discriminant analysis demonstrated only grade III-IV IVH to be independently associated with LCVA (p <.05). We conclude that there is an association between LCVA and grade III-IV IVH. We speculate that LCVA is most likely a sequelae of severe IVH. Further investigation, including follow-up data, is needed to determine the significance of this association.