Real-time cranial sonography via the anterior fontanelle was used serially over a 3- and 6-week period, respectively, to evaluate two infants who developed multicystic encephalomalacia secondary to Citrobacter neonatal meningitis. Sonographic findings included heterogeneous parenchymal echogenicity, gyral prominence, periventricular hypoechoic areas from which cystic spaces evolved, and development of hydrocephalus. Serial cranial computed tomography over the same time period confirmed the sonographic observations in each case.