Objectives: Recently, there has been a growing interest in the relationship between sleep disturbances and suicidality in major depression. Sleep disturbances are one of the 'modifiable risks' for suicide in major depression. The present study examines whether there is a relationship among nightmares, suicide attempts, and melancholic features in unipolar major depressed patients. Methods: One hundred (49 males and 51 females) depressed patients with melancholic features and 49 (23 males and 26 females) patients without melancholic features were included in the study. All patients were classified as those who attempted suicide at least once during current depressive episode and as those who never attempted. Results: Melancholic attempters had higher rates of nightmares, middle, and terminal insomnia than melancholic non-attempters. There was no significant difference between non-melancholic patients with and without suicidal attempts in terms of the frequency of all types of insomnia and nightmares. Limitations: This study does not have polysomnographic records for sleep variables. Conclusions: Feeling worse in the morning than later in the day may be related to the intervening dream content and affect and predict suicidal tendency. Melancholia may be associated with increased risk of suicide attempts due to repetitive and frightening dreams. © 2006 Elsevier B.V. All rights reserved.