Suicide attempters and completers may represent different but overlapping groups of distressed individuals. Although depression is related to an increased risk of suicide, the presence of depression may not discriminate suicide attempters from completers. The present study compared suicide attempters and suicide completers on symptoms of depression, the presence of suicide-related variables and stressful life events.The present study sought to identify the key differences between 50 suicide attempters and 50 completers, all diagnosed with a Major Depressive Disorder at the time of their suicidal act.Suicide attempters and family member informants of suicide completers participated in a thorough psychosocial evaluation. To maximize comparisons with completers, suicide attempters were subclassified based on the lethality of their attempt.Suicide attempters and completers were similar on most measures of depressive symptoms. However, suicide completers were significantly more likely to use alcohol or drugs prior to their suicidal act and they were more likely to leave a suicide note. Suicide completers were significantly more likely to have encountered significant job stress and financial problems.The present findings have documented several similarities and differences between suicide attempters and suicide completers. Future research may help to clarify the key warning signs that reflect the risk of completed suicide in adults who have been diagnosed with a Major Depressive Disorder.