We have assessed the effect of adverse childhood experiences on the lifetime prevalence of suicide ideation in a cross-sectional study involving 182 patients aged 18 to 44 years, consecutive attenders at an A&E review clinic. All participants were interviewed by a psychologist using standardised questionnaire instruments addressing participants' demographic characteristics, drug use, depressed mood, eight major categories of adverse childhood experiences (including physical, emotional and sexual abuse) and suicide ideation. The response rate was 73%. In multivariate logistic regression analyses, those with a history of two or more forms of childhood adversity relative to those with none were at increased risk of depressed mood (OR = 5.5, 95% CI = 2.3-13.3) and suicide ideation (OR = 3.5, 95% CI = 1.5-8.3). The findings emphasise the need to set suicide prevention within the broader context of society's obligation to protect children from physical, emotional and sexual abuse.