Abnormal zinc metabolism in a 6-year-old male patient with Landau-Kleffner syndrome (acquired aphasia and convulsive disorder) is the subject of our report. We describe a significant decrease of erythrocyte and plasma zinc levels in the patient as compared with normal. Red blood cell zinc content is normally 38.5 ± 2.7 μg/g hemoglobin v 16.5 μg/g hemoglobin found in the patient. Plasma zinc level is 94.6 ± 10.4 μg/dL in normal in comparison with 50.4 μg/dL in the patient. Normal oral zinc tolerance test performed on the patient precludes altered zinc absorption or increased urinary loss. The possible connection between abnormal zinc metabolism and the pathophysiology of Landau-Kleffner syndrome is discussed. (J Child Neurol 1987;2:28-30).