Background: Diabetes mellitus (DM) could be an important factor in identifying people with a high risk of tuberculosis (TB) in Chile, thus, we aim at studying the force of the relationship of these two pathologies. Methods: A case-control study was undertaken using secondary data from the SSMS population group. The cases (n = 473) were defined as first episodes of confirmed TB patients 15 years and older, registered between 2006 and 2009. The controls (n = 507) were non TB cases, residents in the same Health Service area, randomly selected from the population registered under the public health care system. Risk factors were taken from SIGGES (system for health information and management) files. Logistic regression adjusting for age and social vulnerability was used to estimate the OR (± CI 95%). Results: The higher frequency of DM among cases OR = 3.3 (95% CI 2.2-5.0) was confirmed. The inclusion of confounders -age, health insurance and residence in poorer counties- in the model yields produced an adjusted OR = 2.3 (95%CI 1.5-3.6). Conclusions: DM is strongly associated with TB in Chilean settings, therefore it may be anticipated that adding this diabetes criteria in screening of TB would help to increase earlier and inclusive diagnosis.