OBJECTIVE - To determine whether type 2 diabetes contributes to the presence of depressive and anxiety disorder diagnoses in low-income adults with hypertension, asthma, and/or arthritis. RESEARCH DESIGN AND METHODS - Using a cross-sectional design, this study administered a structured diagnostic interview to low-income primary care patients diagnosed with type 2 diabetes, hypertension, arthritis, and asthma, as well as to those with no chronic illness (n = 326), to determine the 12-month prevalence of depressive and anxiety disorders. A logistic regression (LR) model was used to assess whether a diagnosis of depression and/or anxiety was associated with type 2 diabetes after adjusting for known risk factors. RESULTS - A high prevalence rate of depressive and/or anxiety disorders was found in the total sample (29%) and in all three illness groups: type 2 diabetes (36%), other chronic illnesses (24%), and no chronic illness (31%). Using LR, a main effect was detected for illness group when age and education were controlled (χ2 = 22.66, df 4, P = 0.000). Specifically, the odds of occurrence of a depressive and/or anxiety disorder in those with comorbid type 2 diabetes were twice that in the nondiabetic, chronically ill comparison group (odds ratio 2.26, 95% CI 1.28-4.01, P = 0.005). CONCLUSIONS - These results suggest a positive contribution of type 2 diabetes to increased rates of depressive and/or anxiety disorders in patients with hypertension, asthma, and/or arthritis and support prior research that type 2 diabetes may serve as an indicator of depression and anxiety in low-income adults treated in primary care clinics.