The aim of this study was to investigate the effectiveness of Individual Cognitive Behavior Therapy (ICBT) in treating patients with mood disorders with suicidal ideation. A total of 69 patients (48 females, 21 males) with the diagnoses above were randomly allocated to either the group of Treatment As Usual (TAU)+ICBT (n=33) or the TAU group (n=36). All participants completed the Beck Depression Inventory (BDI), Beck Scale for Suicide Ideation (BSS), Positive and Negative Suicide Ideation Inventory (PANSI), Beck Hopelessness Scale (BHS), and Depression Anxiety Stress Scale-21 (DASS-21). These questionnaires were administered at pre-treatment, midway through treatment (week 4), post-treatment (week 8), and at follow-ups after three months (week 20) and six months (week 32). Factorial ANOVA results showed that the TAU+ICBT patients improved significantly and at faster rate as compared to the TAU group, which showed improvement only from pre to mid treatment on DASS-D and BHS-T measures. The effect size (Cohen's d), for the TAU+ICBT group showed large effect (1.47) for depressive symptoms and suicidal ideation (1.00). These findings suggest that ICBT used in addition to the TAU, was effective in enhancing treatment outcome of patients with unipolar mood disorders as well as, reducing risk for suicide behavior.