Arterial spin labeling (ASL)-magnetic resonance imaging (MRI) and fluorodeoxyglucose (FDG)-positron emission tomography (PET) both have diagnostic value for dementia, particularly frontotemporal dementia (FTD). By using simultaneous FDG-PET/ASL-MRI, we investigated the relationship between brain metabolism and perfusion in FTD, to evaluate their suitability and complementarity. Exploratory analysis of simultaneous FDG-PET/ASL-MRI in 15 dementia patients showed that metabolism and CBF correlate well on a global level, both visually and quantitatively. On a regional level, one-on-one correlations are limited, supposedly to disease-specific regions such as frontotemporal, subcortical and parietal regions. These results will be substantiated in a larger and better differentiated dementia cohort.