Cognitive and behavioural impairments accompanying motor neuron disease (MND) have been reported since the early 20th century.Typically, these changes can be associated with a dysexecutive syndrome or manifest as a frontotemporal dementia (FTD).Although the nature of specific frontotemporal dysfunction in MND remains to be refined, as with the clinical presentation, there is likely to be significant heterogeneity.This talk will review the current state of knowledge regarding the neuropathological and neuroanatomical basis for cognitive dysfunction in MND.Neuropathological findings suggest that cognition in MND mainly affects the frontotemporal network but is also part of a broad clinicopathological spectrum now known as TDP-43 proteinopathies.Functional neuroimaging has supported neuropsychological findings of frontotemporal dysfunction and has also implied the relative involvement of somatosensory areas.Structural neuroimaging has not been able to establish a specific hypothesis of extra-mnotor cortical atrophy beyond the combination of various frontal and temporal areas.The finding of reduction in the integrity of white matter in the frontal and temporal lobes including long association fibres suggests that subcortical involvement may underlie both cognitive and functional changes in ALS.Future perspectives for further investigations will be highlighted.