While suicidal behaviour has been implicated in a plethora of psychiatric disorders including depression, psychoses and substance abuse, its association with adult ADHD is largely under-researched. Given that emotional instability and the high prevalence of comorbid conditions such as mood disorders and alcohol/drug dependence are typical for ADHD, the question of suicide risk must not be neglected in this patient group. A review of the current literature focusing on this issue provides strong evidence that ADHD patients are at a significant risk for experiencing suicidal ideations and committing suicide. For daily clinical practice, it is therefore essential to incorporate this aspect into the diagnostic and therapeutic process and to take preventive measures.