Background: Behavioural changes are a key factor in distinguishing frontotemporal dementia (FTD) from Alzheimer’s disease (AD), however, little is known about the impact of these changes on caregivers. The aim of this study was to compare caregivers’ distress related to behavioural symptoms of AD and FTD. Methods: 47 spouse caregivers of consecutively referred patients with AD and 27 spouse caregivers of patients with FTD participated in this study. Behavioural disturbances in the patient and caregivers’ emotional reactions were measured with the Neuropsychiatric Inventory. Results: Patients with FTD had significantly higher levels of agitation, apathy, disinhibition and aberrant motor behaviour than did patients with AD. High distress scores were found for disinhibition, depression and apathy in caregivers of FTD patients whereas caregivers of AD patients reported patient apathy, depression and anxiety as being severely distressing. Higher mean distress scores were found for disinhibition in the FTD group. Furthermore, caregivers of FTD patients reported higher levels of general burden, and felt less competent than AD caregivers. Conclusions: Caregivers of FTD patients were overall more distressed by the behaviour of their partners than were the caregivers of AD patients.Findings from this study underscore the importance of differentiating between diagnostic groups and specific behavioural domains when focusing on caregiver reactions to problem behaviour.