Recent recommendations for head ultrasound screening suggest limiting exams to infants ≤1250 g birthweight (BW) or 30 wks gestation (GA), because of declining incidence of major intracranial hemorrhage (ICH) and to contain costs. However, cystic periventricular leukomalacia (cPVL) and ventricular enlargement (VE) are strongly associated with adverse neurodevelopmental outcome, may not be associated with ICH, & occur in larger preterm infants(>30 wks GA). These findings are usually seen on late head ultrasounds(HUS) at ≥28 days of age. We therefore reviewed all HUS findings in preterm infants ≤32 wks GA born 1/92 to 6/95 at University Hospital, to develop a rational screening strategy likely to detect cPVL/ VE. Timing, findings, number of exams, and basic clinical information were retrieved. 236 infants≤32 wks GA survived until hospital discharge; 126 were >30 wks GA. Of these, 67 had ≥1 HUS; 59 had none. Of 67 with any HUS, 45 (67%) were obtained before 28 days, and therefore may have been inadequate to detect cPVL. Thus 104 infants >30 wks GA (59 no HUS, 45 HUS < 28 d) did not have imaging needed to determine a true incidence of cPVL. In 1995, 48% of these larger infants had no HUS vs. 25% in 1992, indicating decline in screening. Either cPVL or VE was seen in 8/67 infants (11.9%) with a correctly timed late HUS. Of these, 2 had normal initial studies. The 8 with cPVL/VE had BW 1040-1765 g (1501±241), 2-9 days of ventilation or CPAP(4±3), and 2-54 total days in oxygen (13±17). We conclude cPVL and VE occurs in infants >30 wks GA despite initially normal studies or benign clinical courses. However, the true incidence of cPVL/VE is unknown with recent trends of decreased screening. We recommend that to detect cPVL or VE one HUS be done at ≥28 days of age in all preterm infants ≤32 weeks gestation, including those with BW >1500 g or GA >30 wks, regardless of results or timing of prior studies.