The dentate fascia of the hippocampus was studied in 25 infants with pontosubicular necrosis and in 21 control cases without hypoxic cerebral lesions. Of the control cases 19 were completely normal and 2 showed one single necrotic cell in the granule cell layer. In contrast 15 of the cases with pontosubicular necrosis showed varying degrees of neuronal karyorrhexis in the dentate fascia. The severity of these changes largely parallelled those in the subiculum but there were exceptions to this rule. It is concluded that the dentate fascia is frequently involved in pontosubicular necrosis.