Neuropathological findings in the brain of a 4-month-old child born to a chronic alcoholic mother were microcephaly, uncovered rostral region of the insula, disordered arrangement of nerve cells in the cerebral cortex, cerebellar abnormalities, and glial meningeal heterotopies. In addition, impregnantion of neurons by means of the Golgi method showed decreased numbers of dendritic spines and predominance of spines with long, thin pedicles on cortical pyramidal cells. A significant reduction in the number of DS (Student t test; p less than 0.001) on the apical dendrites of layer V pyramidal neurons was demonstrated in this patient when compared with similar counts performed in the brain of controls aged newborn, three months and four months. Reduced numbers of DS and abnormal geometry of spines observed in this child suggest that an abnormal maturation of nerve cells may occur in children, like it has also been demonstrated to occur in rodents, as a consequence of chronic ethanol consumption during gestation.