Background: The present study aimed at determining the role of Intolerance of Uncertainty and positive Metacognitive Beliefs in Obsessive Compulsive and Depression disorders.

Methods: Seventy patients with obsessive compulsive disorders and depression referred to psychiatry clinics of Baghiyatallah and Taleghani hospitals of Tehran were chosen via convenient sampling and were compared with 35 normal individuals (age range of 20 to 38) on intolerance of uncertainty scale and positive metacognitive beliefs subscale. Then data were analyzed using one way variance analysis and Scheffe post-hoc test. Research design of present study was Ex post facto research.

Results: Patients suffering from obsessive compulsive disorder and depression gained higher scores than normal group in intolerance of uncertainty scale. Regarding positive metacognitive beliefs, patients with obsessive compulsive disorder gained higher scores than depressive patients; and depressive patients gained higher scores than normal group.

Conclusion: Considering the crucial role of intolerance of uncertainty and positive metacognitive beliefs in obsessive compulsive disorder and depression, they should receive special attention in treatment.