OBJECTIVE: There is much research on risk factors of suicide, but studies about what can play a protective role on suicide are limited. This study was conducted to investigate the impact of depression and emotional intelligence on suicidal ideation of patients with depression. We focused more on the role of emotional intelligence as a protective factor. METHODS: The participants (n=100) underwent a psychiatric interview which included the Mini International Neuropsychiatric Interview and the Columbia University Suicide Severity Rating Scale (C-SSRS). Beck's Depression Inventory (BDI) was also completed. For measuring emotional intelligence, both a self-report questionnaire (the Adult Emotional Quotient Test, AEQT) and an objective measurement based on ability model (Emotional Literacy) were conducted. RESULTS: In linear regression analysis, depressive symptom score was significantly associated with suicidal ideation. It was also shown that 'emotional expression' of AEQT and 'emotion perception' of Emotional Literacy are significantly associated with suicidal ideation. CONCLUSION: Against our expectation that emotional intelligence would be a protective factor on suicidal ideation, emotional expression and emotion perception might rather be a risk factor for suicidal ideation. The limitations of this study and suggestions for further research are also discussed.