The aim of this study was to report initial clinical experience with a 320-slice CT scanner and to perform an image quality evaluation. 26 patients with presumptive cerebrovascular pathology underwent 320-slice CT. Single-rotation CT of the head, incremental CT angiography (three-dimensional (3D) CTA) as well as four-dimensional whole-brain CTA (4D CTA) and whole-brain CT perfusion (CTP) were performed and the resulting images were assessed for quality and compared with those obtained with 64-slice CT protocols. 320-slice CT neuroimaging could be performed in all cases. The image quality of 320-slice CT of the head and 3D CTA was inferior to that of the 64-slice protocols. The image quality of 4D 320-slice CTA was rated as inferior to both 320- and 64-slice 3D CTA. 4D CTA-CTP imaging added information with pivotal clinical implications. 320-slice CT neuroimaging is feasible technique that permits whole-brain 4D imaging and has the potential to identify pathologies with altered haemodynamics. However, image quality is a limitation of this technique at present.