Objectives To explore associations between carer burden and characteristics of (1) the informal carer, (2) the person with dementia, and (3) the care support network in 8 European countries. Design Cross-sectional study. Setting People with dementia judged at risk of admission to long-term care (LTC) facilities in 8 European countries (Estonia, Finland, France, Germany, Netherlands, Spain, Sweden, United Kingdom). Participants A total of 1223 people with dementia supported by community services at home or receiving day care or respite care and their informal carers. Measurements Variables regarding the informal carer included familial relationship and living situation. Variables relating to the person with dementia included cognitive functioning (S-MMSE), neuropsychiatric symptoms (NPI-Q), depressive symptoms (Cornell depression scale), comorbidity (Charlson Comorbidity Index), and physical functioning (Katz Activity of Daily Living [ADL] Index). The care support network was measured using hours of caregiving (ADLs, instrumental ADLs [IADLs], supervision), additional informal care support, and service receipt (home care, day care). Experience of carer burden was recorded using the Zarit Burden Interview. Logistic regression analysis was used to determine factors associated with high carer burden. Results Carer burden was highest in Estonia (mean 39.7/88) and lowest in the Netherlands (mean 26.5/88). High burden was significantly associated with characteristics of the informal carer (family relationship, specifically wives or daughters), of the person with dementia (physical dependency in ADLs; neuropsychiatric symptoms, in particular nighttime behaviors and irritability), the care support network (hours of caregiving supervision; receipt of other informal care support) and country of residence. Conclusion A range of factors are associated with burden in informal carers of people with dementia judged to be on the margins of LTC. Support for informal carers needs to take account of gender differences. The dual challenges of distressed behaviors and difficulties in ADLs by the person with dementia may be addressed by specific nonpharmacological interventions focusing on both elements. The potential protective effect of additional informal support to carers highlights the importance of peer support or better targeted home support services. The implementation of appropriate and tailored interventions to reduce burden by supporting informal carers may enable people with dementia to remain at home for longer.