Crossed cerebellar diaschisis (CCD) in stroke patients has been associated with worse neurological performance and outcome, but clinical routine CCD imaging is limited. We therefore tested the diagnostic value of blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) and T2* perfusion weighted-MRI in patients with unilateral symptomatic cerebrovascular steno-occlusive disease exhibiting crossed cerebellar diaschisis. Secondly, we assessed the clinical significance of a CCD diagnosis based on BOLD-CVR imaging. BOLD-CVR is a valid clinical diagnostic tool for CCD, whereas perfusion MRI derived parameters were shown to be unsuitable. Furthermore, stroke patients exhibiting CCD showed a worse neurological performance and outcome, unrelated to stroke volume.