The purpose of this paper was to explore the time spent on caring by families of persons with dementia in Sweden. As part of a European Commission project, interviews were carried out on a sample of 92 carers, caring for persons with dementia. The interviews focused on time spent on caring, IADL, ADL and surveillance, as well as formal support received and used. Informal care, measured as hours spent caring, was about 8.5 times greater than formal services (299 and 35 h per month, respectively). Approximately 50% of the total informal care consisted of time spent on surveillance (day and night). Formal care input and informal support, in terms of ADL increased with dementia severity. A regression analysis showed that dementia severity, behavioural disturbances and coping were associated with the amount of informal care. This study gives some new perspectives on informal care giving for persons with dementia and support strategies in general. Some carers do carry a very heavy 24 h responsibility. This aspect of caring must be addressed by the development of well-targeted respite and relief support programmes.