In the USA, the use of advance directives (ADs) has been studied extensively, in order to identify opportunities to increase their use. We investigated the prevalence of ADs and the factors associated with formulation of an AD in The Netherlands, using samples of three groups: the general population up to 60 years of age, the general population over 60 years of age, and the relatives of patients who died after euthanasia or assisted suicide. The associated factors were grouped into three components: predisposing factors (e.g. age, gender), enabling factors (e.g. education) and need factors (e.g. health-related factors). We found that living wills had been formulated by 3% of younger people, 10% of older people, and 23% of the relatives of a person who died after euthanasia or assisted suicide. Most living wills concerned a request for euthanasia. In all groups, 26-29% had authorized someone to make decisions if they were no longer able to do so themselves. Talking to a physician about medical end-of-life treatment occurred less frequently, only 2% of the younger people and 7% of the older people had done so. Most people were quite confident that the physician would respect their end-of-life wishes, but older people more so than younger people. In a multivariate analysis, many predisposing factors were associated with the formulation of an AD: women, older people, non-religious people, especially those who lived in an urbanized area, and people with less confidence that the physician would respect their end-of-life wishes were more likely to have formulated an AD. Furthermore, the enabling factor of a higher level of education, the need factor of contact with a medical specialist in the past 6 months, and the death of a marital partner were associated with the formulation of an AD.