Associated tuberculosis and diabetes mellitus in Santiago de Chile Metropolitan area Background: Diabetes mellitus (DM) is recognized as an important risk factor to tuberculosis (TB). However, there is significant diabetes under registration among tuberculosis cases which does not allow quantify the magnitude of this group. This study aims to determine the prevalence of DM among TB cases diagnosed in 2012 in Santiago de Chile, metropolitan area and to estimate the association of these two diseases. Method: A cross sectional study was undertaken. TB cases reported in the National Register of Tuberculosis were sought in the Information System for Management of Health Guarantees (SIGGES) to determine we ther or not they had be sides DM. The analysis of prevalence by age, sex and health service area was carried out, prevalence ratio was used to determine the level of association, and incidence rate of tuberculosis among diabetics and non-diabetics was estimated. Results: 23 TB cases were excluded for lack of necessary information, leaving a total of 821 cases.