We discuss a newborn delivered by elective cesarean section who had macrocephaly with severe anemia. The anemia was corrected by exchange transfusion, and the infant, at first, appeared stable but manifested poor feeding and seizures. Transillumination of the skull was negative, although the anterior fontanel was tense. Computerized tomography demonstrated mild hydrocephalus and suggested subdural fluid. Bilateral subdural taps yielded fluid typical for chronic subdural hematoma. To our knowledge, this is the first documented case of intrauterine subdural hematoma developing in the absence of trauma. An analogy is made to the pathogenesis of subdural hematoma after rapid decompression of the ventricular system by shunting procedures for obstructive hydrocephalus.