Diabet. Med. 27, 217–224 (2010) Abstract Aims Depression is common in diabetes, but the scope of the problem and associated correlates are not well established in specialist diabetes care. We aimed to determine the prevalence of depression among adult outpatients with Type 1 (T1DM) or Type 2 diabetes (T2DM) using both self‐report measures and a diagnostic interview, and to establish demographic and clinical characteristics associated with depressive affect. Methods A random sample of 2055 diabetes out‐patients from three diabetes clinics was invited to participate. Depressive affect was assessed using the World Health Organization‐5 Well Being Index (WHO‐5), the Centre for Epidemiologic Studies‐Depression scale (CESD) using predefined cut‐off scores, and depressive disorder with the Composite International Diagnostic Interview (CIDI). Associations between depression and patient characteristics were explored using regression analyses. Results Seven hundred and seventy‐two patients completed the depression questionnaires. About one‐third of T1DM patients and 37–43% of T2DM patients reported depressive affect (WHO‐5). The prevalence of depressive affect (CESD) was 25% and 30% for men and women with T1DM, and 35% and 38% for men and women with T2DM, respectively. Based on the CIDI, 8% of T1DM patients (no gender difference) and 2% of men and 21% of women with T2DM suffered from a depressive disorder. Depressive affect was associated with poor glycaemic control and proliferative retinopathy in T1DM, while non‐Dutch descent, obesity and neuropathy were correlates in T2DM. Conclusions Depressive symptoms and major depressive disorder constitute a common comorbid problem among Dutch out‐patients with T1DM or T2DM and appear particularly common in migrants and women with T2DM.