The Landau-Kleffner Syndrome (LKS) is characterized by acquired receptive aphasia and EEG abnormality with onset between the ages of 3 and 8 years. This study presents neuropsychological assessments in 5 children with LKS. The aims were (1) to specify the neuropsychological deficits characteristic of these children; and (2) to clarify the nature of the receptive aphasia by comparing nonverbal and verbal auditory discrimination. Receptive aphasia was present in all children. Retardation, poor motor coordination, hyperkinesia, and conduct problems were frequent but variable. All children exhibited a dissociation between the discrimination of environmental sounds and phonological auditory discrimination, the latter being more impaired than the former. This suggests that the primary deficit of the receptive aphasia is an impairment of auditory phonological discrimination rather than a generalized auditory agnosia. (JINS, 1998, 4, 566–575.)