One hundred surviving infants with birthweights less than or equal to 1200 g were examined longitudinally, using real-time ultrasonography of the brain. Five infants were diagnosed as having cavitary periventricular leukomalacia (PVL). One infant expired within a month following discharge; the remaining four entered a follow-up program and received developmental assessments. Three infants had moderate-severe spastic diplegia and the fourth had spastic quadriplegia. Cavitary PVL can be diagnosed in vivo and predicts future motor delay or cerebral palsy. Since the typical site of PVL involves the optic radiations, and the incidence of visual-perceptual disturbances is high in premature infants, further research is needed to explore the possible relationship between these two abnormalities.