This study describes the prevalence of suicidal ideation and attempted suicide in a representative survey among adults in Denmark and gives the proportion of people reporting a suicide attempt that results in contact with the health care system. The data for the 1994 Danish national health interview survey were collected by personal interview and a self-administered questionnaire. A subsample of 1362 individuals participated in the part of the survey that addressed suicidal behaviour (64% of the random sample). The results show that 6.9% reported having had suicidal thoughts within the past year. Averaging across all age groups the overall prevalence of people reporting ever having made a suicide attempt was 3.4% and the one-year prevalence was 0.5%. Suicidal ideation was more prevalent among young people than among older people, whereas ever-attempted suicide showed no age gradient. Both suicidal ideation and ever-attempted suicide were more prevalent among economically inactive people (e.g. unemployed) and among unmarried or divorced people. We estimate that 50-60% of suicide attempts reported in a representative, national survey become known to the healthcare system.