Two cases of von Recklinghausen neurofibromatosis with a hitherto unreported association of ventriculomegaly and a Chiari type I malformation are described. Both cases had skeletal abnormalities at the cervicomedullary junction, contributing to neurological symptoms in 1. The literature on nontumor-related ventriculomegaly in neurofibromatosis is reviewed. The Chiari type I malformation should be considered as a cause of nontumoral ventricular enlargement in patients with von Recklinghausen neurofibromatosis.