Meningeal carcinomatosis remains a challenging diagnosis to make, with both cerebrospinal fluid (CSF) analysis and radiological methods having a limited sensitivity. We aimed at describing a possible diagnostic sign of multislice CT angiography (MS-CTA) in the diagnosis of meningeal carcinomatosis. Upon retrospective analysis of MSCT angiographies of the brain, a conspicuous sign of the vessels of the interhemispheric fissure was noted in five patients. Cranial MSCT angiographies were performed with a standardized protocol (120 kV, 200 mA s, collimation of 4x1 mm, table feed per rotation 4 mm). We injected 120 ml of nonionic contrast medium as a bolus, and data acquisition was started after a fixed delay of 35 s. In order to elucidate the finding, correlation with clinical follow-up and/or CSF findings was performed for all patients. In five patients there was a blurring, an increased number, and a pathologic configuration of the vessels of the interhemispheric fissure. All five patients with this sign had clinical signs and symptoms of meningeal carcinomatosis. Three patients had positive CSF cytology, one further patient had follow-up spinal MRI 6 weeks later demonstrating meningeal carcinomatosis. One patient declined lumbar puncture. MS-CTA has the capacity to demonstrate a pathologic configuration of the vessels of the interhemispheric fissure in patients with meningeal carcinomatosis. This sign may serve as an indicator of meningeal carcinomatosis and should raise the suspicion of this disease entity.