Depression is a mental disorder that often exists within patients with diabetes mellitus. Several studies displays that the patients with type 2 diabetes mellitus has an increased risk of minor and major depression. The symptom of diabetes complications and the self-management behavior are predicted to be the contributing factors that influence depression in the patient with type 2 diabetes mellitus. This research employs ordinal logistic regression method to determine the most prominent factor affecting depression and to detect the level of depression according to the said factors. The result of this research displays that depression occurs in 43.6% of the patient with type 2 diabetes mellitus in Cipto Mangunkusumo hospital. The factor that influences depression in the patients of Cipto Mangunkusumo hospital with type 2 diabetes mellitus is only diabetes complication, which consist of hypoglycemia, ophthalmology, and sensory neuropathy.