This was a record-linkage analysis of a birth cohort to examine the association between self-reported self-harm in adulthood and childhood maltreatment (CM) as prospectively notified to authorities and self-reported on the Child Trauma Questionnaire. There were 2507 participants at 30-year follow-up with data on both CM and self-reported self-harm including an intent to die. Of the participants, 304 (12.1%) had self-harmed at some time in their lives while 150 (4.2%) had wanted to die. The prevalence of self- and agency-reported maltreatment was 513 (20.5%) and 143 (5.7%) respectively. On adjusted analyses, CM irrespective of reporting source showed significant associations with both suicidal outcomes. Physical and emotional abuse showed the strongest associations while findings for neglect were mixed. The only association for sexual abuse was for self-reported maltreatment and intent to die but numbers may have been under-powered.