BackgroundThere are few prevalence studies of suicide attempts and non-suicidal self-harm (NSSH).AimsWe aimed to estimate the prevalence of thoughts of NSSH, suicidal thoughts, NSSH and suicide attempts among 18- to 34-year-olds in Scotland.MethodWe interviewed a representative sample of young adults from across Scotland.ResultsWe interviewed 3508 young people; 11.3 and 16.2% reported a lifetime history of suicide attempts and NSSH, respectively. The first episode of NSSH tended to precede the first suicide attempt by about 2 years. Age at onset of NSSH and suicide attempt was younger in females. Earlier age at onset was associated with more frequent NSSH/suicide attempts. Women are significantly more likely to report NSSH and suicide attempts compared with men.ConclusionsOne in nine young people has attempted suicide and one in six has engaged in NSSH. Clinicians should be vigilant, as suicide attempts and NSSH are relatively common.Declaration of interestNone.