Objective. To determine the prevalence of depression in Mexican adult diabetics and to identify factors associated to the depression. Research design. Protective survey. Setting. Four Mexico City hospitals (Clinica San Pedro de los Pines IMSS, Centro Medico Nacional Siglo XXI IMSS, Hospital Gea Gonzalez SSa and Centro de Salud Margarita Chorne SSa). Study units. 79 patients with diabetes mellitus type 2. Main measurements. The Beck Depression Inventory was used as a measure of depression. We used sociodemografic variables (age, gender, marital status, religion, education, occupation, socioeconomic status) and disease variables (years of diagnosis, other chronic medical conditions and compliance with therapeutic regimens) as the independent variables of depression. Results. Mean age was 59 +/- 11 years (SD) and 58 (73%) were females. The frequency of depression was 46%. Factors associated to depression were: females (OR = 3.67, CI = 1.07-13.3, p = 0.03) and years of diagnosis above 15 (OR = 3.08, CI = 0.91-10.8, p = 0.07). Conclusions. Frequency of depression was high (46%). Gender and years of diabetes diagnosis were factors associated to depression.