Although chronotype has been associated with suicidal behavior, current research suggest that this relationship may be mediated by other factors. The aim of this study was to assess whether chronotype, specifically morningness, may predict suicidal behavior and whether this relationship may be mediated by general mental health, depressive and anxiety symptoms, and/or social functioning among young adults. The study group comprised 306 students: 204 (65.8%) women, 101 (32.6%) men and one who chose not to identify with either option (0.3%). The participants completed The Composite Scale of Morningness, The General Health Questionnaire, 30-item version, Suicide Acceptance Questionnaire and The Suicidal Behaviors Questionnaire-Revised. Correlations between the continuous variables of interest revealed a weak, but significant, negative association between morning affect (CSM) and suicidal behavior (SBQ-R); a moderate positive association was found between suicidal behavior (SBQ-R) and depression/anxiety, and a weak one between suicidal behavior (SBQ-R) and interpersonal relations (GHQ-30). The models predicting suicidal behavior, and chronotype-related variables as predictors of suicidal behavior, were then tested. Although the morning affect predicted suicidal behavior, this effect became irrelevant when combined with mental health characteristics: psychopathological symptoms of depression and anxiety and the quality of interpersonal relations. Our findings imply that the role of chronotype is secondary to general mental health: mental disorder symptoms should be considered as the core risk factors for suicide and serve as the focus for suicide risk assessments.