Chronic lung disease is associated with several poorly defined risk factors for impaired cerebral development. Late neonatal onset of subependymal hyperechogenic areas in the caudothalamic groove has been reported in association with dexamethasone treatment and postnatal cytomegalovirus infection. We reviewed charts of 18 patients who developed subependymal hyperechogenicity beyond the first week of life, as well as charts of 79 patients belonging to a prospective surfactant study group. Thirteen of the 18 patients with subependymal hyperdensities had been treated with surfactant and were all found in the subgroup with chronic lung disease. In the surfactant-treated patients who did not develop chronic lung disease, we could not find any patient with subependymal hyperdensities. From the remaining five patients with ultrasound lesions, but who were not treated with surfactant, three had developed chronic lung disease. There was no evident association with dexamethasone treatment or cytomegalovirus infection. Our results support the idea of an association between chronic lung disease and the described echographic lesions in the caudothalamic groove, but the nature of the link between them is still unclear.