Purpose of review The correct classification of non-Alzheimer's dementia is crucial to study disease mechanisms, predict disease progression and test disease-specific treatments. Brain atrophy assessment with morphometric MRI is currently the gold standard for in-vivo localization of neurodegeneration. Structural and functional connectivity biomarkers are becoming increasingly available. This review emphasizes the potential applications of MRI in the main non-Alzheimer's dementia such as dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD). Recent findings MRI can predict co-occurrence of Alzheimer's disease pathology in DLB patients and pathological subtypes in patients with FTD. Innovative applications of brain connectivity are providing neural substrates explaining the network-dependent spread of pathology in non-Alzheimer's dementia. Advanced MRI can be relevant in characterizing the temporal sequence of the earliest functional and structural brain changes in individuals at risk for neurodegenerative non-Alzheimer's diseases. Summary Morphometric MRI is clinically applied at an individual level for the differentiation between Alzheimer's and non-Alzheimer's dementia and may help in predicting underlying pathology, which will be critical for the success of disease-modifying therapies. Longitudinal, multimodal MRI studies are required to demonstrate whether advanced magnetic resonance techniques can be reliable outcome measures to monitor disease progression in clinical trials, starting from the presymptomatic stage. © 2018 Wolters Kluwer Health, Inc. All rights reserved.