Aims: To explore: (1) The relationship between children admitted to our paediatric department as a result of suicide attempts with acetaminophen and their parents and friends. (2) The extent to which the children had attempted to speak to their parents about their problems before their suicide attempts. (3) The frequency of self-mutilation among children with suicidal behaviour. (4) The purposes and reasons for childhood suicide attempts. Methods: A retrospective case-control study based on medical records and in-hospital child psychiatric assessments at the Paediatric Department, Hillerød Hospital, Denmark, 2006-2011. Study group: 107 children, 11 to 15 years old. Control group: 59 age- and gender-matched children. Results: 43.5% experienced a dissociated parental relationship characterized by the inability to speak to their parents about any problems, compared with 2% in the control group. There was a significant association between a dissociated parental relationship and 'the feeling of not being heard' (p = 0.004), the discovery of the suicide attempt (p = 0.008), the reasons for the suicide attempt (p = 0.006), academic school problems (p = 0.03), and the child's relationships with friends (p = 0.02). Prior to their suicide attempts, 41.5% of the children had attempted to speak to their parents about their problems but felt that they were not heard. There was a significant association among 'the feeling of not being heard' and the purpose of the suicide attempt (p = 0.002) and self-mutilation (p = 0.002). Forty percent mutilated themselves repeatedly. Conclusions: A consistently impaired parent-child relationship, 'the feeling of not being heard', and self-mutilation are identifiable early risk factors that require increased concern and attention among professionals who work with children.