Absence of the falx cerebri is a rare radiological finding, which is generally described in relation with varying degrees of holoprosencephaly or other structural central nervous system anomalies. We present a case of non-syndromic, asymptomatic absence of falx cerebri in an elderly patient, which was discovered incidentally on a computed tomography examination of the head. The superior sagittal sinus was narrowed, but present. Relevant anatomic and embryological considerations are discussed, as well as potential implications for clinical practice.