While studies investigating factors associated with carer burden suggest that intellectual impairment and behavioural disturbance in the care recipient are more demanding for the carer than physical impairment, comparative research findings are equivocal. Family carers of people with a long-term illness or disability were identified through a survey of 26,000 households in Victoria, Australia. Focusing on carers of those aged over 50 years, three subsamples were selected: 186 carers of relatives with physical impairment only, 182 carers of those with diagnosed memory loss and 117 carers of those with intellectual impairment diagnosed as dementia. Carers of physically impaired relatives reported better health, greater life satisfaction, and less overload, negative affect, family conflict, anger and resentment than carers of those with intellectual impairment, whether labelled as dementia or not. Despite lower impairment levels in the care recipient, carers of those with undiagnosed memory loss reported more resentment about their caring role than carers of those with a diagnosed dementia. The effects on the carer of significantly greater impairment in the dementia care recipient group may be ameliorated by having a diagnosis, bringing with it the potential for increased understanding and tolerance. Fortunately, negative feelings predictive of a sense of burden are subject to a range of interventions: providing information to promote understanding; counselling to tackle negative feelings and family conflict; guidelines to deal with behaviour problems and physical aspects of caring; and community services to reduce overload.